Ryan Hall's third place was the best finish by an American since Meb Keflezighi's third in 2006. His Olympic marathon teammate Brian Sell of Woodbury, Pa., finished second among Americans, in 14th place with a time of 2:16:31. Patrick Rizzo of Rochester Hill, Mich., was the third US finisher, right behind Sell in 15th with a time of 2:17:05.

Here are the official times for the top 10 men's finishers:

1. Deriba Merga of Ethiopia, 2:08:42
2. Daniel Rono of Kenya, 2:09:32
3. Ryan Hall of Mammouth Lakes, Calif., 2:09:40
4. Tekeste Kebede of Ethiopia, 2:09:49
5. Robert Kiprono Cheruiyot of Kenya, 2:10:06
6. Gashaw Asfaw of Ethiopia, 2:10:44
7. Solomon Molla of Ethiopia, 2:12:02
8. Evans Cheruiyot of Kenya, 2:12:45
9. Stephen Kiogora of Kenya, 2:13:00
10. Timothy Cherigat of Kenya, 2:13:04

Here are the top times in the wheelchair races:

MEN
Ernst Van Dyk of South Africa, 1:33:29
Masazumi Soejima of Japan, 1:36:57

WOMEN
Wakako Tsuchida of Japan, 1:54:37
Diane Roy of Quebec, 2:01:27

Among those in the field today is the legendary Bill Rodgers, a four-time Boston winner and the most successful American marathoner of all time. "Boston Billy" is widely credited with helping to create the running boom of the 1970s and 1980s. It's his first Boston Marathon since 1999, but he told the Globe "I'm not racing it, I'm running it." He hopes to break four hours, which won't even make him a contender in his age group. But that's not what matters to him. He's competing to raise awareness of prostate cancer. Rodgers had intended to run Boston last year to celebrate his 60th birthday, but couldn't because he was recovering from prostate cancer surgery.

The top 10 finishes in the women's division:
1. Salina Kosgei, 32, of Kenya: 2:32:16
2. Dire Tune, 23, of Ethiopia: 2:32:17
3. Kara Goucher, 30, of Oregon: 2:32:25
4. Bezunesh Bekele, 26, of Addis Ababa, Ethiopia: 2:33:08
5. Helena Kirop, 32, of Kapenguria, Kenya: 2:33:24
6. Lidiya Grigoryeva, 35, of Cheboksary, Russia: 2:34:20
7. Atsede Habtamu, 21, of Addis Ababa, Ethiopia: 2:35:34
8. Colleen De Reuck, 45, of Boulder, Colorado: 2:35:37. With this finish, De Reuck won the women's Masters Division.
9. Alice Timbilili, 26, of Moiben, Kenya: 2:36:25
10. Alina Ivanova, 40, of Cheboksary, Russia: 2:36:50

Notable: A third American, Sheri Piers, 37, of Falmouth, Maine (Joan Benoit's town) finished in 11th place with a time of 2:37:04.

The major races are over, but runners will continue to cross the finish line for four or five more hours.

The wind was a big factor in the women's race, according to women's winner Salina Kosgei of Kenya. "The wind got stronger, so it was very hard," she said after receiving her laurel wreath, "but we tried."

In the men's race, Tekeste Kebede of Ethiopia was fourth in 2:09:49, followed by Robert Kiprono Cheruiyot of Kenya in 2:10:06, Gashaw Asfaw of Ethiopia in 2:10:44, Solomon Molla of Ethiopia in 2:12:02 and Evans Cheruiyot of Kenya in 2:12:45.

The 2:32:16 time posted by women's winner Salina Kosgei of Kenya was the slowest time recorded by a woman in Boston since monetary prizes started in 1986.

Kenyan Daniel Rono has finished second in the men's race in 2:09:32, with American Ryan Hall third. Hall's time was 2:09:40. Americans took third in both the men's and women's races.

American Ryan Hall is charging to the finish, but doesn't look like he will catch Daniel Rono for second place.

Ethiopia's Deriba Merga has won the 113th Boston Marathon. His time was 2:08:42.

Ethiopia's Deriba Merga is heading down Boylston Street.

Salina Kosgei, 32, of El Marakwet, Kenya, has captured the women's crown in the 113th Boston Marathon, edging defending champion Dire Tune, 23, of Addis Ababa, Ethiopia by less than two seconds. Tune is on the ground at the finish line, being tended to by medical staff. Kara Goucher, 30, of Portland, Oregon, finished third, several seconds after Tune. Kosgei finished in 2:32:16.

Men's leader Deriba Merga of Ethiopia is entering Kenmore Square. His lead has increased to a minute, and he looks certain to erase the disappointment of a fourth-place finish in last year's Olympic Marathon.

Dire Tune, the defending champion, has moved to the front of the women's field.

Deriba Merga continues to look strong as the men pass through Coolidge Corner. He has a 50 second lead, and it's his race to win. Robert Kiprono Cheruiyot, Ryan Hall, Tekeste Kebede and Daniel Rono are all battling for second. Merga passed the 24-mile mark in 1:57:14.

For more than two decades, the Boston Marathon finish line had been 759 feet high. Miles before runners arrived at the Prudential Center, they could see the skyscraper looming above the Boston skyline, a marathoner’s Mecca. But once John Hancock signed on as principal sponsor in 1985, Mecca moved down the road to Copley Square and has remained there since. The final two champions to break a tape at the Pru were Geoff Smith and Lisa Larsen-Weidenbach, the last American woman to win.

Kara Goucher and Dire Tune are running right beside each other -- they ran the last mile in 5:11. Bezunesh Bekele of Ethiopia has dropped back, but Salina Kosgei of Kenya is right behind the leaders.

The BAA has announced that 23,205 athletes started the marathon today. It expects about 98 percent of them to finish.

Deriba Merga continues to lead as the men enter Cleveland Circle. His last mile was 4:54. 20-year-old Kenyan Robert Kiprono Cheruiyot has joined Daniel Rono and American Ryan Hall about 20 seconds back.

As the women approach Kenmore Square, longtime Boston Marathon observers will recall one of the most infamous races in marathon history: The Rosie Ruiz race of 1980. Here's how John Powers of the Globe Staff describes it:

She definitely ran the final 385 yards. What Rose Ruiz left out was the first 26 miles. “I never see this woman,” said Jacqueline Gareau, who thought she’d won the race until she spotted Ruiz wearing the victor’s wreath. Nor did anyone else see her before the mysterious New Yorker apparently jumped in at Kenmore Square. “I ran the race,” Ruiz insisted, but nobody else believed her. Eight days later, she was stripped of the title and Gareau was declared the winner. When she returned 25 years later as grand marshal, Gareau stepped out of the car and symbolically jogged across the finish line. “I think: I’m like Rosie now,” she said. “Is this right?”

As the crowds thicken as the women get closer to Kenmore Square, it's not difficult to spot Kara Goucher; at 5 feet, 7 inches tall, she towers over the Ethiopians and Kenyans who are keeping pace with her.

In the men's race, Deriba Merga continues to press the pace as he heads down the backside of Heartbreak Hill towards Cleveland Circle. He has about a 30-second lead over Daniel Rono and Ryan Hall, who are neck-and-neck for second and third. Merga's last mile was 4:56.

Just as a reminder, an American has not won the Boston Marathon since 1985, when Lisa Weidenbach won the women's division.

The women are 22 miles into the race, and as the wind from the east picks up, the women are tucking in behind the leader, American Kara Goucher of Oregon. Defending champ Dire Tune of Ethiopia is running just off Goucher's right hip.

Deriba Merga of Ethiopia, who finished fourth -- just out of the medals -- at the Beijing Olympics, is charging up Heartbreak Hill in Newton. With five miles to go his lead is increasing over Daniel Rono, Solomon Molla, and Ryan Hall.

Kara Goucher, leading the women, just grabbed a long drink of water as the women cross the trolley tracks in Cleveland Circle.

The women are heading to Cleveland Circle, where marathoner Patti Catalano had a memorable -- and unfortunate -- encounter with a police horse in 1981. As related by John Powers of the Globe Staff, Catalano didn’t think she was racing at Suffolk Downs until she literally ran into a horse’s rear at Cleveland Circle. “I don’t know if I would have won,” said Catalano, who was leading the women’s race when crowds pushed the police mount into her path. “But it would have been a heck of a race.” Though Allison Roe eventually caught her and won by more than a minute, Catalano still set an American record of 2:27:51 in her third consecutive runner-up finish. “What are you going to do?” she concluded. “That’s the beauty of the marathon. You run with what you’re dealt. Just like life.”

Ryan Hall has moved up into third place, but is still 15 seconds behind leader Deriba Merga, who is running smoothly and still looks good. Merga has a 12-second lead on a fading Solomon Molla. Robert Kipkoech Cheruiyot, the three-time defending champion, has fallen off the pace

Kara Goucher and defending champion Dire Tune are in the lead of the women's race as they finish the Newton hills and start the downhill trek to Brighton.

Deriba Merga of Ethiopia is now the clear leader as the men's race heads into the Newton hills. He has opened up a few yards of space on Daniel Rono of Kenya. The lead pack is beginning to break apart as the fast early pace takes its toll. The leaders passed the 19 mile mark in 1:32:41. Merga's most recent mile was 4:46. Early leaders Ryan Hall and Robert Kipkoech Cheruiyot are in the middle of the chase pack.

Although American Kara Goucher briefly surged ahead of the nine or so women who are still bunched together, she now is running just behind fellow American Colleen De Reuck. The lead men, who started 28 minutes behind the elite women, are running such a faster pace than the women that they are just 3 miles behind.

Deriba Merga and Daniel Rono have picked up the pace and broke away from the pack as the men turned onto Commomwealth Avenue in Newton. Solomon Molla has dropped back to third. American Ryan Hall is in fifth, about 18 seconds back.

The men's pack is down to 11 and beginning to spread out as they cross Route 128 and head towards Newton-Wellesley Hospital. Deriba Merga and Solomon Molla, both Ethiopians, have a few-step lead on defending champion Robert Kipkoech Cheruiyot and Daniel Rono of Kenya. American Ryan Hall has fallen back to ninth place, about 10 seconds off the lead.

Wakako Tsuchida has won her third consecutive Boston Marathon in the women's wheelchair division, finishing with a time of 1:54:37.

Stephen Kiogora and Timothy Cherigat have made a move as the men approach Route 128. They have taken a lead of a couple of yards on the rest of the pack.

The surprising Masters runner Colleen De Reuck, 45, of Colorado, has regained the lead in the women's race. Kara Goucher is in second place.

Stephen Kiogora of Kenya had taken the lead for the moment in the men's race as they pick up the pace in the downhills past Wellesley Center. The last mile was run in 4:53, and they have just crossed over Route 9. Timothy Cherigat caused a stir in the press truck by crossing to the other side of the course from the pack and running on his own, but after a few seconds everyone joined him.

There are 10 women bunched together at the16-mile point, and at this point, the field is led by Helena Kirop, 32, of Kapenguria, Kenya. She has never run Boston before -- or anywhere in the US, for that matter -- but has placed in the top three in her last seven marathons. Coming off her personal best last September in Berlin, she could have enough momentum to attack Heartbreak Hill.

Lidiya Grigoryeva, 35, of Cheboksary, Russia, the 2007 Boston winner with a time of 2:29:18, has surged to the women's lead, with Kara Goucher, 30, of Portland, Oregon, right behind her. The women have passed the 25K mark.

Today is the 1,000th race for Boston Marathon icons Dick and Rick Hoyt. For more than 30 years, Dick Hoyt has pushed his son Rick, who is a quadriplegic and has cerebral palsy, across the finish lines of marathons, triathalons, and road races around the nation, including 27 Bostons. They have a personal best for the marathon of 2:40:47, a time most runners can only dream about. In 1992, they biked and ran across America together, completing the 3,735 miles in 45 days. Rick, 47, is a graduate of Boston University. Dick, 68, a retired lieutenant colonel in the Air National Guard, keeps up a busy schedule of motivational speeches. Here's a Q&A with the pair.

The lead pack of 12 men has just passed the halfway mark in 1:03:38. Robert Kipkoech Cheruiyot is leading, but the rest, including American Ryan Hall, are right on this shoulder. They are heading into the long downhill in Wellesely Hills.

Elva Dryer, 37, of Gunnison, Colorado has fallen off the pace in the women's race and now lags the lead pack.

As the men passed Wellesley College Deriba Merga took the lead for a brief time before being reeled in by the pack. They are now approaching the halfway mark.

The men's lead pack is down to 12 as they pass Wellesley College. Gashaw Asfaw has taken over the lead, with Robert Kipkoech Cheruiyot in second. Ryan Hall has dropped into the middle of the lead pack, though he still looks good. The pace has slowed a bit. They are on track to run about 2:07.

Ernst Van Dyk has won the men's wheelchair division in 1:33:29.

The women's race continues to evolve slowly, with three Ethiopians in the lead: Bezunesh Bekele, 26; Dire Tune, 23, who is trying to repeat as Boston's female champion, and Elfenesh Alemu, 33.

If Evans Cheruiyot or defending champion Robert Kipkoech Cheruiyot win today, they will vault to the top of the 2008-9 World Marathon Majors men's leader board. Both have 25 points. Robert Cheruiyot got his for winning Boston last year; Evans Cheruiyot won last October in Chicago. The series leader at the moment is Olympic gold medalist Samuel Wanjiru of Kenya, with 40 points. Besides his win in Beijing, Wanjiru placed second in last year's London Marathon. Six other runners would vault to at least a tie for second if they win: Ryan Hall, Daniel Rono, Timothy Cherigat, Tekeste Kebede, Deriba Merga, and Gashaw Asfaw.

The Boston Marathon is part of the three-year old World Marathon Majors Series, which also includes next week's London Marathon, and the marathons in Berlin, Chicago, and New York. Runners placing in the top five of these races earn points on a sliding scale: 25 for a win, 15 for second, 10 for third, 5 for fourth, and 1 for fifth. Points are also awarded for performances at the IAAF World Championship and Olympic marathons. The series is a bit odd in that the $1 million prize purse is given out every year, based on performances for the past two years. So, points won today count not only towards the 2008-2009 prize, awarded this year, but also towards the 2009-2010 prizes, awarded next year.

Barring an accident, Ernst Van Dyk appears poised to win his record-tying eighth Boston Marathon in men's wheelchair. He passed the 24-mile mark in Coolidge Corner in 1:25:20.

As the 12 top female runners attract most of the media attention as they race from Hopkinton to Boston, some in the crowd will be keeping an eye out for a 50-year-old woman from Amherst, NH, who is running her first Boston Marathon -- with psoriatic arthritis.

Just a few years ago, Cathy Merra was in so much pain she would often have trouble sleeping through the night. She would walk down stairs one step at time, and needed help from her husband or two sons with simple tasks such as opening jars.

Affected by psoriatic arthritis since her early 20s, Merra had previously controlled the disease - which caused her joints to stiffen and swell - through exercise. But by age 46, it had worsened to the point where she "walked like a 90-year-old," she said.

"It's not until the pain goes away that you really realize how bad it is," Merra told Globe correspondent Maggie Cassidy. "Everybody has something that you have to deal with and that was just my thing."

She controlled the pain with a weekly injection she began taking three years ago, and by last October, she was ready to try the Maine Marathon -- and ran 3:16, good for fourth overall and first in her age group.

The pain treatment was important for Merra, who has had room in her heart for running for more than a decade. After her older son, Anthony, who now competes for Columbia University, started running for local clubs at age 9, Merra started a running club at Amherst Middle School. She now coaches a Junior Olympic cross-country team and the Souhegan High School track team.

Members of those teams will be on hand Monday to cheer on Merra in her first Boston Marathon. When she tapes on bib No. 7493, the significance won't be lost.

"I grew up watching the Boston Marathon, watching Bill Rodgers," she said. "It's been a dream of mine."

The lead pack of men is entering Natick Center, with American Ryan Hall still in first place. They went through 15K in 44:44 and the ten-mile mark in 48:06 -- a blistering 2:05:44 pace. That would shatter Robert Kipkoech Cheruiyot's course record of 2:07:14.

Andrea Hatch of Castine, Maine, will be bidding to lengthen her string of consecutive Boston Marathon finishes to 32 (not counting her unofficial jaunt in 1977). The 65-year-old Hatch, who's tied for 17th on the list, is the only female member of the Quarter Century Club, the 36 runners who've finished at least 25 straight here.

American hopeful Kara Goucher, 30, of Portland, Oregon, has never run Boston, so she test-ran the course in February, when she was here for the Reebok Indoor Games.

She was captivated by it.

"I love New York so much, but there are times when you're running there when you feel insignificant," she told John Powers of the Globe. "All those bridges, super-tall buildings, concrete everywhere. Boston is more intimate. The roads are closer, you're running through neighborhoods with trees."

With rare exceptions, like the stretch from Newton Lower Falls (over Route 128) to Woodland, you're also running through a wall of sound for the second half of the race, often with spectators standing four and five deep along the curbs. If Goucher is up with the leaders today, the noise will be deafening. There hasn't been an American woman in that position in years (Deena Kastor, undone by stomach cramps, was fifth two years ago). In fact, there hasn't been a top-three finish since Kim Jones in 1991.

Goucher's victory in the Lisbon Half Marathon in March, by a minute and a half over Salina Kosgei, 32, of El Marakwet, Kenya -- an opponent today -- was auspicious, coming as it did after a wretched week of practice. What she learned there, Salazar says, was that she can win even without perfect preparation. No matter what happens here, Boston will be Goucher's last big one for a while, since she hopes to start a family soon and be back in form for the next Olympics in 2012. "This is it for me," she says. "This is my goal for the year."

Not that it's going to be a gimme for Goucher, who'll be going up against defending champion Dire Tune, 23, of Addis Ababa, Ethiopia; 2007 champion Lidiya Grigoryeva, 35, of Cheboksary, Russia, and Kosgei. "It's unrealistic to believe that I can just trounce everyone," she realizes. "There are some really accomplished people there and they've been around the block."

If there weren't, Goucher wouldn't be interested. She can pick up a laurel wreath from a Back Bay florist. "I want to run against the best," Goucher says. "I don't want to lie to myself and fool myself into thinking I'm better than I am." The possibility of getting her butt kicked is one of the attractions. "I don't want to go and win Boston because they didn't invite anybody good," she says. "What does that mean? It doesn't mean anything. You want to win Boston because it's one of the greatest races of all time."

The $150,000 winner's check is alluring, but that's not what entices her. "I honestly can say from my heart that it's not about making money," says Goucher. "It's all about living the passion." What she proved to herself in New York is that she could run 26 miles without putting herself into intensive care. That race was about survival, she says. This one will be about identity - and possibly posterity. "I have to find out," Kara Goucher says, "who I am as a marathoner."

Defending Boston women's champion Dire Tune, 23, of Addis Ababa, Ethiopia has moved into the lead as the women run past screaming Wellesley College students and pass the halfway mark. But other elite runners, including Kara Goucher of Oregon, are just a step behind.

Brian Sell, who was a member of the 2008 US Olympic marathon team along with current leader Ryan Hall, is in 14th place, about two minutes behind the lead pack. Luke Humphrey is the third-place American, in 23rd overall.

At the 25K mark, women's wheelchair racer Wakako Tsuchida led Shirley Reilly by a minute and a half. Reilly was racing neck-and-neck with Diane Roy.

The lead pack of 13 men is so far in front as they pass from Framingham into Natick that the rest of the race isn't even in sight. They are running a blistering 2:05:00 pace. Ryan Hall passed the eight-mile mark in 38:14. Three-time defending champion Robert Kipkoech Cheruiyot is right on his shoulder.

The female runners still are bunched together: Elva Dryer of Colorado, Lidiya Grigoryeva of Russia, Masters entrant Colleen De Reuck of Colorado, Kara Goucher of Oregon, defending champion Dire Tune of Ethiopia, Elfenesh Alamu of Ethiopia, and Mary Akor of California. The women are running at a pace for a marathon finish time of 2:36.

As the men's wheelchair race passed the 25K mark in Wellesley, Ernst Van Dyk had a two minute and 30 second lead. Masazumi Soejima, Krige Schabort and five others were battling for second, with all seven separated by a mere second.

With the women's wheelchair race more than half over, Wakako Tsuchida is still ahead, posting a time of 1:04:04 at the 25K mark.

The last of the field is off! It will take about 10 minutes for all 13,000 runners in Wave 2 to cross the starting line, at which point the cleanup will begin in earnest. In a few hours Hopkinton will return to being the quiet, picturesque New England town it is the other 364 days of the year.

The lead pack of men has separated themselves from the rest of the field. Besides leader Ryan Hall the pack includes Gashaw Asfaw, Robert Kipkoech Cheruiyot, Tekeste Kebede, Deriba Merga, Robert Kiprono Cheruiyot, Solomon Molla, Daniel Rono, Stephen Kiogora and masters division leader James Koseki. They went through six miles in 28:26.

Wave 2, which contains the remaining 13,000 runners, is about to start in Hopkinton. These back-of-the-packers will get the gun at 10:30.

Barely 10 weeks after a disappointing 10th-place finish in the 10,000 meters in the Olympics in Beijing last summer, Kara Goucher's new coach, legendary runner Alberto Salazar, ramped up her weekly mileage to 100 and signed her up for New York, the last major marathon of the season. "Alberto said, 'Let's just do it. Get your feet wet. Let's jump in. It won't be the perfect preparation, but it's enough time,' " Goucher told the Globe's John Powers.

As race day drew closer, though, Goucher began worrying. What if she ended up being road kill in Queens, where she was born? "I was excited, but I was so scared," she recalls. "There was a part of me that was so afraid that I'd be the greatest hoax of all time. They're giving me all this attention, they're paying me. I don't even know if I can do it."

Salazar and Nike sports psychologist Darren Treasure worked as a tag-team on Goucher's psyche. "Alberto said, 'This is where you're going to shine, this is where you belong,' " she says. "Darren and I laughed about it. He said, 'If you bomb you go home with your money and they're never going to invite you back.' "

Besides the distance, the field was daunting - world record-holder Paula Radcliffe, Olympic runner-up Catherine Ndereba, and defending World Marathon Majors titlist Gete Wami, plus three former champions and Dire Tune and Rita Jeptoo, who'd both won Boston. The doubting whispers in Goucher's head that frequently bugged her returned.

"I don't want to find out that I'm not that good," she said. "Self-confidence is something I've always battled. I've definitely gotten better at it, but it's hard to take risks. But that's where it pays off."

Salazar, who told Goucher to stick close to Radcliffe from the gun, now thinks his advice was mistaken. "Kara was rigid right from the start," he says. "She was staring at Paula's shoulder blades." Yet Goucher, who'd beaten Radcliffe in a half-marathon in England the previous year, hung with her, albeit with trepidation. "Paula's the greatest road runner of all time," she says. "I knew she was going to just put the hurt to us. It wasn't a fun little jaunt in the park for her. There was that sense in the back of my mind that this could end at any second."

Once Radcliffe put the hammer down in Manhattan she ran away from everybody, winning by the biggest margin (1 minute 47 seconds) in nine years. Though Goucher kept up with the other contenders -- finishing third in 2:25:53, faster than any American woman in New York Marathon history and a U.S. debut record -- she paid for it in pain.

"I kept waiting for the wheels to fall off and they did," she says. "The last 55 minutes were awful. It was unbelievable. After I finished and everybody was patting me on the back, I thought I was going to die. I told my husband, 'I'm going to pass out right here and no one's even going to be aware.' But after I finally got some liquid into me, I thought, you know, I could have gotten second (she finished 10 seconds behind 40-year-old Ludmila Petrova of Russia). And the next morning I was, when are we going to do this again? I need to do this again."

Maybe you should run Boston, Salazar suggested. It was a no-brainer, Goucher figured. "I wanted to race in the States," she says. "That was first and foremost. What are the biggest ones? New York and Boston, right?" Boston wouldn't be anything like New York, Salazar told her. The topography and tumult are unique. "He said there'd be craziness all around me," she says.

In the men's wheelchair race, Ernst Van Dyk is well ahead as he passes the fire station in Newton, heading into Heartbreak Hill. Masazumi Soejima of Japan is in second.

The women's lead continues to change hands minute by minute, four or five women trading spots: Colleen DeReuck of Colorado, Elva Dryer of Colorado, Tomoe Yokoyama of Tokyo, Atsede Habtamu of Ethiopia, and Bezunesh Bekele of Ethiopia. The pace is relatively slow; 37:06 through 10K. Kara Goucher of Oregon and defending women's champion Dire Tune of Ethiopia are right behind.

American Ryan Hall led the men on a scorching pace through the 5K mark. His split of 14:33 is about 20 seconds below record pace. Hall passed ran the fourth mile in 4:43, with a large pack still on his heels.

Even though female marathoners have chopped an hour off Boston's winning time in the 43 years since Roberta Gibb of Massachusetts recorded an unofficial time of 3:21:40, no woman in the past six Boston races has come close to the 2:20:43 posted by Margaret Okayo of Kenya in 2002, when she upset defending champion and countrywoman Catherine Ndereba. In fact, since Allison Roe of New Zealand broke the 2:30 mark in 1981 (2:26:46), the finishing times for women running in Boston have hovered in the mid-2:20s.

Sub-2:20 women's marathons have been achieved 14 times:

> The aforementioned Ndereba has accomplished the feat three times -- twice in Chicago, and once in London.
> The great British marathoner Paula Radcliffe has broken 2:20 four times, and holds four of the top five best times, including the women's world record of 2:15:25, set in London in 2003.
> No other woman has run faster than 2:20 more than once.

Given today's headwinds, which will increase as the runners get closer to Boston, it is unlikely that any woman will break 2:20 today. But someday?

Bezunesh Bekele, 26, of Addis Ababa, Ethiopia, has jumped out to the lead in the women's race. This is her debut in Boston. After placing second in Dubai in 2008 (her marathon debut), she returned in January to claim her first victory (2:24:02). She also finished seventh in Chicago last October. Bekele is the fourth-fastest Ethiopian women's marathoner of all time.

The men's pack is spreading out a bit, with Ryan Hall, Gashaw Asfaw and Robert Kipkoech Cheruiyot trading the lead back and forth. They ran their third mile in 4:44, a slightly slower pace. Asfaw is looking particularly good.

It's now been 20K, and defending Boston wheelchair champion Wakako Tsuchida has not relinquished her lead among the female wheelchair racers. Her 20K split time was 50:11.

Robert Kipkoech Cheruiyot is out to do something Clarence DeMar, Bill Rodgers, Cosmas Ndeti, Uta Pippig, and Fatuma Roba could not: win four years in a row. DeMar, Rogers, Ndeti, Pippig, and Roba all won three straight, but failed when they tried to make it four. DeMar won from 1922 to 1924, but finished second in 1925. Rodgers won from 1978-1980, but finished third in 1981. Ndeti won from 1993 to 1995, but finished third in 1996. Pippig won from 1994 to 1996, but faded to fourth in 1997. Roba won from 1997 to 1999, but finished third in 2000.

The men's leaders went through the second mile in a blistering 4:32, with Ryan Hall leading a pack of 13 runners that includes most of the contenders.

Today's women's elite field, which numbers 12 runners from four countries (Ethiopia, Kenya, Russia, and the US), includes two former Boston champions: Last year's victor, Dire Tune, 23, of Addis Ababa, Ethiopia, who bested the field with a time of 2:25:25; and Russia's Lidiya Grigoryeva, 35, the 2007 Boston winner with a time of 2:29:18.

Two of the elite women running today raced in last summer's Olympic marathon, with Salina Kosgei, 32, of El Marakwet, Kenya, finishing 10th and Ethiopia's Tune ending up in 15th place. Although Kara Goucher, 30, of Portland, Oregon, the top US contender, also was at Olympus, she ran in the 5,000- and 10,000-meter races.

Ernst Van Dyk of South Africa has increased his lead in the men's wheelchair race to a minute over Masazumi Soejima of Japan. Van Dyk went through the half-marathon mark in Wellesley in a time of 43:49.

A pack of 13 runners was leading the men's race when it went through the one mile in 4:38. Ryan Hall was in front, followed by Gashaw Asfaw and defending champion Robert Kipkoech Cheruiyot.

The female elite runners are running two-by-two, with Americans Elva Dryer and Colleen De Reuck in front; Portland resident Kara Goucher running near Russian racer Lidiya Grigoryeva.

American Ryan Hall has jumped to the early lead in the men's race. He is striding well in the long downhill following the start. On his heels is Gashaw Asfaw of Ethiopia and a pack of dozens.

They're off! The 2009 Boston Marathon men's race is under way. The top runners are sprinting downhill on Route 135 towards Ashland, hoping to put some distance between themselves and 13,000 runners of the first "wave", who are right behind them.

At the four-mile mark, the women's field continues to be led by Elva Dryer and and Colleen De Reuck, both of Colorado. Dryer ran the first four miles in 24:07.

Other men to watch include Ethiopian Deriba Merga, who finished fourth, just out of the medals, in the Beijing Olympics, and earlier this year won the Houston Marathon. Kenyans Daniel Rono and Benjamin Maiyo are consistent performers. Rono has finished in the top three in all seven marathons he's run; Maiyo has finished second in three marathons, including Boston in 2006.

A US runner hasn't won the men's race since Greg Meyer in 1983, but Ryan Hall's credentials as the fastest man in the field give him as good a shot as anyone in a long time. Fellow Olympian Brian Sell was part of the last good showing by Americans, when he, Meb Keflezighi, and Alan Culpepper finished fourth, third, and fifth respectively in the 2006 race.

The elite men are on the starting line along Rte. 135 in Hopkinton. Their race will begin in a few minutes. Among those in the front row is Robert Kipkoech Cheruiyot, who is wearing the gold singlet that signifies the defending champion. If he wins today he will be the first person to win four consecutive Boston Marathons. He is also the course record holder, having run 2:07:14 in 2006. Joining him, just to make life difficult for reporters and announcers everywhere, are two other Cheruiyots: Robert Kiprono Cheruiyot, only 20 years old and the winner of the 2008 Frankfort Marathon, and Evans Cheruiyot, winner of last year's Chicago Marathon and one of the world's best half marathoners. None of them are related.

The resume of 30-year-old elite runner Kara Goucher of Portland, Oregon, is remarkably diverse. She won the NCAA cross-country title while at the University of Colorado, plus the outdoor crowns at 3,000 and 5,000. She made the Olympic team in both the 5,000 and 10,000. She won the mile at the last two Millrose Games. Last month, she ran away from the field in the Lisbon Half Marathon. And her New York marathon performance (2 hours 25 minutes 53 seconds), the fastest-ever there by a US woman, produced the first podium finish by a domestic runner in 14 years.

"I like changing it up," Goucher told John Powers of the Globe. "A lot of what I love about the sport is the challenges, going to different places and trying different things. I can't imagine not doing that."

What she hadn't imagined was the marathon. In fact, Goucher's distance results had been so discouraging amid a series of injuries that she'd considered dropping down to the 1,500. After both she and husband Adam missed making the Olympic team for Athens, they decided to switch their training base from Colorado to Oregon and work with Alberto Salazar and his Nike Oregon Project.

"We said, 'Let's try something new,' " recalls Goucher, who knew so little about Salazar's stellar racing days (three New York and one Boston marathon titles plus an Olympic appearance) that she had to Google him to find out. "I was drowning. I thought, anything is better than where I'm at. I'd completely lost faith in everything I was doing. I was starting to lose faith in myself. Alberto was upbeat, he was positive. He said, 'You can get healthy, you can get better.' I just had to go for it."

Her breakout came in 2006 when Goucher posted a series of personal bests, most notably a 31:17:12 clocking in her second attempt at the 10,000. Only Kastor had been faster among US women, which caught Salazar's eye. The best 26-milers, he believes, are those who were superb on the track. "You're going to make a great marathoner," Salazar had told her after her first 10,000. "I was like, gag me," she remembers. "But Alberto didn't push it. He said, someday. He never forced it on me."

Goucher still considered herself primarily a track runner, especially after her medal in the 10,000 at the pre-Olympic world meet in Osaka, the first by an American in the event. So her 10th-place finish in Beijing last year left her crushed and confused. "I was devastated by how it went," says Goucher, who finished ninth in the 5,000 a week later. "I thought I was going to medal, and I was a minute behind the winner. I was so NOT going to win."

Don't worry, her coach told her, you're going to be a great marathoner. "I was like some dad trying to be nice to her and make her feel good," says Salazar. "It was a stupid thing to say at the time and she was furious at me for saying it right then. But part of me was actually relieved. If Kara had gotten fourth or fifth she might have thought, OK, I can medal again."

Unlikely, reckoned Salazar, who told Goucher that she'd need a perfect race even to win a bronze at either distance. "Look at Tirunesh Dibaba and Meseret Defar - do you think you can beat them?" he asked. "You and a bunch of other people will be fighting for third. You go to the marathon and you have a legitimate shot at winning. There is nobody who is clearly superior to you."

As they passed the 10K mark in Framingham, Ernst Van Dyk led the men's wheelchair race. Masazumi Soejima of Japan was second, 40 seconds back. Rafael Botello Jimenez of Spain was in third, nearly a minute behind Van Dyk.

Back at the start in Hopkinton, the first "wave" of the race's main body is being assembled. At the front are the elite men, including defending champion Robert Kipkoech Cheruiyot and American hopeful Ryan Hall. Being assembled in corrals behind them are the best of the rest -- the roughly 13,000 men and women with the fastest qualifying times. They will get the starting gun at 10 a.m. The second wave, made up of the 13,000 runners with the slowest qualifying times, is still back at the athletes' village, on the grounds of the Hopkinton High and Middle school complex. They will step off at 10:30.

At the 10K mark, Wakako Tsuchida is still in front with a race time of 23:18. Competitors Shirley Reilly and Diane Roy are close behind.

Six-time champion Ernst Van Dyk is building up his lead in the men's wheelchair race. He 10K split, by the train station in downtown Framingham, was 19:58. He passed seven miles in 22:47. Masazumi Soejima of Japan is in second, 30 seconds back.

Elva Dryer, 37, of Gunnison, Colorado, is at the front of the elite women, but at the two-mile mark, Tomoe Yokoyama, 32, of Tokyo, had the lead.

Wakako Tsuchida has led the female wheelchair racers throughout, recording a time of 18:55 through five miles.

What does an elite marathoner like Ryan Hall do the day before a race? Hall ran for about 35 minutes in the morning, then wrote in his blog that he would take it easy in his hotel room most of the rest of the day, praying and reading. The one change in his routine? "I plan to eat in the cafeteria at the Athlete Village. I'm thinking rice tonight instead of pasta. I have never done this before, usually I load up on pasta the night before [a race], but I feel like rice and think it will be a good change for me." After dinner he and his wife might watch a movie, Hall wrote, but it would be lights out by 9 p.m.

Kara Goucher of Portland, Oregon, is near the head of the pack as the women pass the 1-mile mark. Goucher, one of only two American women in the elite field, has been reading what she calls "the Boston book," immersing herself in more than a century's worth of lore about the annual footrace hereabouts. Clarence DeMar. The Kelleys, elder and younger. Boston Billy. Bobbi Gibb and Kathy Switzer. The Duel in the Sun and Joanie's Run. Catherine The Great. The women at Wellesley, the firehouse turn, Heartbreak Hill and the Eliot Lounge.

"All of the history and all the amazing performances that have gone on there," the woman who'll be the top American hope in Monday's 113th marathon told the Globe's John Powers. "I want to have a chapter in there so bad."

If the 30-year-old Goucher wins, she'll be the first domestic champion -- man or woman -- since Lisa Larsen-Weidenbach in 1985, the last year before the Boston Athletic Association began awarding prize money. "I'd like to be the one that does it," she says. "I want to be that person."

By winning here, Goucher would continue the American distance-running revival that began with Deena Kastor's Olympic bronze medal in 2004 and her subsequent triumphs in Chicago in 2005 and London in 2006, and was followed by Goucher's global bronze in the 10,000 meters in 2007 and Shalane Flanagan's Olympic bronze last year. "Kara has the eye of the tiger," says Bill Rodgers, the four-time men's champion here. "She's going for the win, and that's what it takes."

A victory also would be a huge step in Goucher's evolution as a marathoner, which began with a startling third-place finish last year in New York in her debut at the distance. "I want to be a marathoner, I want to be in that club," she says. "But I don't just want to be a marathoner. I want to be a distance racer."

It's been 26 years since an American won the men's half of the Boston Marathon, and there haven't been many years in the interim when the top American runners have even competed. This year is different. Two of the country's top talents, Ryan Hall and Brian Sell, both members of last year's Olympic team, are in the field, and Hall is among the favorites. Hall's 2:06:17 at last year's London Marathon is not only the second-fastest time ever by an American, it's faster than anyone else in the field has ever run.

Hall has been enjoying his celebrity status since arriving in Boston last Thursday, signing autographs, meeting marathon legend Bill Rodgers, and on Saturday throwing out the first pitch before the Red Sox game at Fenway Park. In the blog he keeps for his shoe sponsor, Asics, Hall called his visit to Fenway "truly a sweet experience."

Ernst Van Dyk continues to lead the men's wheelchair race. The defending champion went through five miles, on the Framingham-Ashland line, in 16:05.

The BAA has introduced a few new wrinkles this year, including putting the names of elite athletes on the fronts of their racing bibs, instead of numbers. Numbers have been relegated to the backs of bibs. Officials said the change will make it easier for spectators and TV viewers to follow the race and cheer on their favs. The 26,000 non-elites, however, will sport numbers front and back, as is traditional.

In the men's wheelchair race, Ernst Van Dyk went through the 4 mile mark in 12:35. He's closing in on the Ashland-Framingham line.

Two-time female wheelchair champ Wakako Tsuchida is leading the field after 5K with a time of 11:47. The wheelchairs have passed through Ashland and are heading into Framingham.

The elite female runners are off, with many spectators cheering for American Kara Goucher, 30, of Portland, Oregon. But last year's champ, Dire Tune, 23, of Addis Ababa, Ethiopia, is the favorite.

Men's wheelchair leader Ernst Van Dyk has gone through the one mile mark in 4:33. He's now heading into Ashland. Van Dyk is trying for a record-tying eighth Boston Marathon win.

The Boston Marathon is an international event, drawing 4,725 foreign entries from 85 countries. That's 18 percent of the total field. Canada is the best represented nation after the US, with 2,417 runners. There are 324 Brits, 218 Germans, 175 Mexicans, 165 Japanese, 163 Italians, 112 Irish, 104 South Koreans and 97 Frenchmen. The Canadian city of Toronto, a distance running hotbed, has 264 entries by itself, more than any other city besides Boston and New York.

The wheelchair racers are off, on their way to Copley Square in Boston. Because the race begins with a steep downhill, the BAA has been using what it calls a "controlled start" since 1988, the year after a chain-reaction crash dumped several athletes (including the eventual men's champ) from their chairs. The racers are paced for the first half mile, until the course levels out.

The wheelchair racers are lined up at the start. Their race will begin at 9:22. Both the men's and women's champions from 2008, Ernst Van Dyk of South Africa and Wakako Tsuchida of Japan, are returning. A win by Van Dyk would be his eighth, tying him with fellow wheelchair athlete Jean Driscoll for the most Boston Marathon wins ever. He is expected to be pressed by former winner Krige Schabort. Tsuchida is looking to win for the third straight time. Her chief competition is expected to come from Diane Roy and Shirley Reilly.

Wheelchair racer Diane Roy of Canada is hoping for her first Boston win; she finished second in 2005, 2006, and last year, when she came in 8 minutes behind two-time champ Wakako Tsuchida of Japan.

After the 2006 Marathon, Roy went on to win the worlds, then set a Canadian record and personal best of 1:43:49 in the Oita Marathon in Japan.

She has competed in Boston "on and off" since 1998. "I like the course because it can be fast," she told the Globe in 2007. "But the last 10K is very hard. There are a lot of hills, and that is tough for me."

Roy spent the first 17 years of her life with a passion for sports and adventure. Then a car accident left her without the use of her legs, but it didn't destroy her love of competition. She began racing four years later when a friend suggested she try it. "I did it and loved it right away," she said.

Also competing today is wheelchair racer Shirley Reilly, who finished third in 2006 but out of the running in 2007.

The oldest competitor is Regina Tumidajewicz of Amsterdam, N.Y., who is 82. She began running at the age of 54, and in nearly 30 years has competed in more than 700 road races, including 50 marathons. She has never dropped out of a race.

Today's field is 59% men, 41% women. The average age of official runners is 41. There are 28 competitors who are 18 years old, the minimum age allowed by the BAA for medical reasons. (Though one 18-year-old and six 19-year-olds have actually won the race.) At the other extreme, there are eight runners in their 80s. Among the octogenarians is Keizo Yamada of Japan, who won the race in 1953 at the age of 24.

There are 33 wheelchair entrants this year, up from a mere 16 finishers last year. Though this reverses several years of decline in the size of the field, the number is still far behind the mid-1990s, when as many as 89 competitors crowded the starting line. Seven-time champion Ernst Van Dyk of South Africa has blamed the smaller fields on the "insane" expense of highly-specialized equipment and travel, and the difficulty disabled athletes have in getting sponsors.

The women's wheelchair racers are scheduled to start at 9:22 a.m., along with the male wheelchair competitors. Leading the field will be Wakako Tsuchida, the defending champ who is going for her third straight Boston victory. She made her Hub debut in 2002, finishing third behind Edith Hunkeler of Switzerland and Christina Ripp of Urbana, Illinois.

Tsuchida, the first professional wheelchair athlete in Japanese history, is also an Olympic-caliber ice sledge speedskater. "I feel honored to be here," she said after the 2002 race. "Heartbreak Hill? It was fun for me. I enjoyed my Boston experience and I want to return next year."

She won her first Boston Marathon in 2007, the first year that Japanese racers swept the wheelchair division: Countryman Masazumi Soejima dethroned South African Ernst Van Dyk, who had won six consecutive Boston Marathons. Tsuchida was competing in her first race since having given birth seven months before the race. She wasn't expected to threaten competitors such as Diane Roy and Shirley Reilly, who had finished second and third respectively the previous year (defending champion Edith Hunkeler was injured and did not race). But neither was able to keep up with Tsuchida, who led the entire race.

Last year, Tsuchida handily won the women's event for the second straight year, leading all of four finishers. She was a wire-to-wire winner in 1:48:32, almost eight minutes in front of runner-up Diane Roy (1:56:18). "The race was almost decided in the first mile," said Cheri Blauwet, 27, who finished third.

"She's always seen Boston as a historic Marathon," said Tsuchida's translator, Kay Horiuchi. "That's one of the reasons why she came. She also believes that the top athletes are here."

Blauwet said the field may have been thin, but that racers still want to come to Boston. "I think Boston could very easily increase its numbers," Blauwet said. "And I think with a little bit of planning and communicating for next year's race, we could have a field that's twice the size of this year's race."

The wheelchair start is only a few minutes away and their State Police motorcyle escort is forming at the starting line. The wheelchairs will be quickly followed at the start by the elite women.

Today's field is 59% men, 41% women. The average age of official runners is 41. There are 28 competitors who are 18 years old, the minimum age allowed by the BAA for medical reasons. (Though one 18-year-old and six 19-year-olds have actually won the race.) At the other extreme, there are eight runners in their 80s. Among the octogenarians is Keizo Yamada of Japan, who won the race in 1953 at the age of 24.

Today's field of more than 26,300 is the second biggest ever. Only the 100th running in 1996 was larger -- its 38,708 entrants is still the world's record for a single marathon. Last year the field was 25,283, and 98 percent of them finished. The blooming of the Boston Marathon into a mega-race has happened relatively recently. A decade ago there were less than half the number of runners who will compete today. The first race, in 1897, had 18 competitors. As late as 1945, during World War II, there were less than 100 entries, and it wasn't until 1968 that there were even 1,000.

With many world-class female marathoners opting to run London's very fast marathon course next Sunday (the 26th), today's Boston field is not as strong as in recent years.

Boston veteran Catherine Ndereba of Kenya -- the only woman to win Boston four times -- is headed to London, where she'll miss the opportunity to run head-to-head with world record holder Paula Radcliffe, who had to drop out with a broken toe.

Also opting for London are former Paris marathon champion Martha Komu of Kenya, with a personal best of 2:25:33; Irina Mikitenko of Germany, Olympic gold medallist Constantina Dita of Romania, China’s Olympic bronze medallist and 2007 London Marathon champion Zhou Chunxiu, double Chicago champion and Ethiopian record holder Berhane Adere, Gete Wami of Ethiopia, and Russians Svetlana Zakharova and Lyudmila Petrova.

Boston's elite field includes defending champion Dire Tune, 23, of Addis Ababa, Ethiopia, wearing bib number F1. Also running Boston is Lidiya Grigoryeva, 35, of Cheboksary, Russia, the 2007 Boston winner with a time of 2:29:18, wearing bib number F6. Grigoryeva won Chicago last year. Her teammate Galina Bogolomova, the Russian national record holder (2:20:47), had to drop out because of an undisclosed injury.

Other elite women on the Boston course today are 2009 Dubai winner Bezunesh Bekele, 26, of Addis Ababa, Ethiopia, wearing bib number F3; Olympian Salina Kosgei, 32, of El Marakwet, Kenya, bib number F4; and top American runner Kara Goucher, 30, of Portland, Oregon, one of only two American women in the elite field, bib number F8. Goucher ran the fastest American debut of all time in New York last fall (2:25:53). She also competed in both the 5,000 and 10,000 meters at the Beijing Olympic Games, finishing ninth and tenth respectively.

Not to be overlooked are Helena Kirop, 32, of Kapenguria, Kenya, third in Berlin the past two years, bib number F5; Atsede Habtamu, 21, of Addis Ababa, Ethiopia, the youngest woman in the elite field who finished second in her Dubai debut earlier this year, bib number F7; Alice Timbilili, 26, of Moiben, Kenya, bib number F9, and two-time Olympian Elva Dryer, 37, of Gunnison, Colorado, bib number F11.

Because the field of runners is so large and Hopkinton so small (the 26,000 official entrants nearly triples its population), organizers hold three separate starts. First to get the gun, at 9:32 a.m., are several dozen elite women runners. Their 28-minute head start gives them a clear path all the way to Boston, and ensures spectators and the TV audience can see them.

The main body of the race is split into two approximately equal sections, called "waves", based on runners' qualifying times. The first wave steps off at 10 a.m. and contains the elite men and all the runners with qualifying times better than 3:34:36. The second wave, with the remaining, slower runners, starts at 10:30. The electronic chips runners must wear on their shoes keeps track of exactly when they cross the starting line, and exactly when they finish, so no one is penalized by the staggered start.

The weather this morning is a mixed blessing. Skies are cloudy and temperatures are cool, which is good for the runners, but there will be a significant headwind. Forecasters say the temperature in Hopkinton will be 43 degrees at the start, with winds of between 10 and 15 miles per hour. The forecast for Boston calls for a temperature of 48-50 degrees, but the wind -- out of the east at 15 to 25 miles per hour -- may be a significant factor. The rain predicted for today is expected to hold off until this evening.