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This NBA prediction model pretty much nailed the Celtics’ regular season

But how did FiveThirtyEight's NBA predictions fare overall?

Former MVP (left) and current MVP (right). Bob Donnan-USA TODAY Sports

COMMENTARY

Well, that was something. After an NBA regular season during which the Warriors won more games than any team in the league’s 66-year history, the second-best team in the league tied the record for most home wins in a single campaign, and the worst team narrowly avoided the worst overall record of all time, many of us are asking who could’ve seen that coming?

And that’s before we even mention the more than 400 three-pointers Stephen Curry hit — breaking the previous single season record, which he also owned, by more than 100 shots! Oh, and his teammate also hit 276 this year, which is third all-time.

It has been quite a year. And while nobody predicted the otherworldly performances of Golden State and San Antonio, both Las Vegas and Nate Silver’s FiveThirtyEight data blog did make preseason forecasts for each team’s win totals.

And, aside from the absolutely bonkers outliers in California and Texas, they both did pretty well.

FiveThirtyEight’s model takes into account an overall rating assigned to each team, adjusts for injuries and expected changes in minutes for certain players, how many days’ rest each team has, and many other factors.

In fact, on the aggregate, the ESPN property out-performed the Vegas over/under betting lines — that is, by my calculations, FiveThirtyEight’s preseason predictions are, on average, about one win more accurate than Vegas is. However, it should be noted that Vegas has the slight disadvantage in setting its over/under for any given team with a .5 decimal to avoid “pushes,” so the Vegas prediction can never be perfectly accurate for any individual team.

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So, without further ado, let’s see how Silver and his crew stacked up against Vegas and actual results, broken up into five categories:

1. Right on the Money (Teams that FiveThirtyEight called pretty much correctly.)

Boston Celtics, 48-34

FiveThirtyEight preseason prediction: 49-33

Vegas Over/Under: 42.5

After a better-than-expected showing following the highway robbery that was the Rajon trade, the superstar-less Boston Celtics are well on their way to becoming a perennial first-round home team. What their ridiculous stockpile of draft picks can do to raise the team’s ceiling, we’ll see. But, for now, as we saw in the one of the best comeback victories in recent memory, the C’s are at least a tough out for anyone looking to win the East.

Atlanta Hawks, 48-34

FiveThirtyEight preseason prediction: 46-36

Vegas Over/Under: 49.5

After winning a lean sixty wins last season — and then losing defensive stalwart and all-around “glue guy” DeMarre Carroll to the Raptors in the offseason — the Hawks regressed as both Vegas and FiveThirtyEight predicted, which is one reason Celtics fans should be optimistic about Boston’s first-round matchup with Atlanta. Here’s an even juicier angle: a first-round exit might convince perennial all-star Al Horford that it’s finally time to take his talents to green pastures, and then maybe, just maybe, he’ll convince someone else to come join him.

Washington Wizards, 41-41

FiveThirtyEight preseason prediction: 41-41

Vegas Over/Under: 45.5

Washington is an interesting case. FiveThirtyEight’s number matches exactly with how they fared this season, but neither Silver’s site nor Vegas could’ve predicted their injury issues, so this is possibly a case of FiveThirtyEight getting it wrong, despite having the accurate win total. Had Bradley Beal and the Washington supporting cast been healthier this year, it’s quite likely they would have been closer to the 45 wins the betting markets had predicted.

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Orlando Magic, 35-47

FiveThirtyEight preseason prediction: 36-46

Vegas Over/Under: 32.5

 

Milwaukee Bucks, 33-49

FiveThirtyeEight preseason prediction: 34-48

Vegas Over/Under: 43.5

FiveThirtyEight wasn’t entranced by the potential next steps for budding superstar Giannis Antetokounmpo and a full injury-year of Jabari Parker. Vegas, on the other hand, picked them to be better than the Celtics! Granted, a healthy Parker and the addition of Greg Monroe might seem like nice additions to a team that squeaked into the playoffs as a six-seed last year, but this team is much more like Orlando than most thought in October. Both are stacked with super-athletic but undeveloped players 24 years old and younger, and both will benefit from adding another lottery selection this summer before testing the market for available veterans.

Brooklyn Nets, 21-61

FiveThirtyEight preseason prediction: 22-60

Vegas Over/Under: 28.5

Everyone, including Vegas, knew Brooklyn would suck. FiveThirtyEight just thought they would suck more than Vegas did. And they were right. (In other news, thanks to Brooklyn’s terrible season, the Celtics are now guaranteed to have no worse than the sixth pick in the draft, and a 96% chance to pick in the top 5.)

2. Wow, that was a (Pleasant) Surprise (Teams that greatly outperformed preseason expectations)

Golden State Warriors, 73-9

FiveThirtyEight preseason prediction: 60-22

Vegas Over/Under: 60.5

 

San Antonio Spurs, 67-15

FiveThirtyEight preseason prediction: 57-25

Vegas Over/Under: 58.5

With such high expectations, it was difficult to envision either of these teams exceeding them by much. After all, there’s only so much room to improve when you’re already the best, right? As reigning MVP Stephen Curry’s legitimate consideration for the Most Improved Player Award suggests, some things in basketball these days simply don’t have explanations.

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Golden State and San Antonio are equally ridiculous. FiveThirtyEight pretty much agreed with Vegas here that they were the two strongest teams in the strongest conference. But jeez.

Toronto Raptors, 56-26

FiveThirtyEight preseason prediction: 44-38

Vegas Over/Under: 45.5

The ESPN property and Vegas agreed on Toronto, and both underestimated the team. Even without major free agent signing DeMarre Carrol for most of the season, the Raptors have been a big surprise, and look to be Cleveland’s biggest playoff threat, thanks to a career year from Kyle Lowry and the continued development of all-star DeMar DeRozan and Lithuanian prospect Jonas Valančiūnas.

Miami Heat, 48-34

FiveThirtyEight preseason prediction: 37-45

Vegas Over/Under: 45.5

Miami is one of FiveThirtyEight’s few misses. The site’s model had them under .500 while Vegas liked them, while both assumed they’d have All-Star center Chris Bosh the entire year. A late-season surge helped them polish off a respectable 48 wins and a (generally meaningless) fifth Southeast Division title in the past six years.

Charlotte Hornets, 48-34

FiveThirtyEight preseason prediction: 39-43

Vegas Over/Under: 32.5

With defensive anchor Michael Kidd-Gilchrist missing all but seven games this season, many assumed Portland East would flounder. But Kemba Walker’s surprise season helped assuage the loss. They new sit at 6th in the East, with a legitimate shot at upsetting the Miami Heat, at least according to Vegas.

Detroit Pistons, 45-37

FiveThirtyEight preseason prediction: 37-45

Vegas Over/Under: 33.5

Stan Van Gundy is no joke.

Portland Trail Blazers, 44-38

FiveThirtyEight preseason prediction: 36-46

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Vegas Over/Under: 26.5

Portland is the surprise team of the year (unless you count Golden State and San Antonio, which you absolutely should) and while FiveThirtyEight liked them more than Vegas did before the season, neither the sharps nor the nerds predicted this kind of performance. After four of their five starters departed the team last summer, they’ve emerged as the only credible threat to pull off an upset the first round of the Western Conference playoffs. Credit Damian Lillard cementing his superstar status and the emergence of CJ McCollum as the best backcourt tandem outside of San Francisco Bay.

Indiana Pacers, 44-38

FiveThirtyEight preseason prediction: 38-44

Vegas Over/Under: 42.5

Thanks to Paul George’s speedy recovery from his gruesome leg injury, and the sudden emergence of Ian Mahinmi as a serviceable two-way player, the Pacers are in the bottom of the playoffs, instead of the bottom of the lottery where many expected them to be.

New York Knicks, 32-50

FiveThirtyEight preseason prediction: 25-57

Vegas Over/Under: 31.5

Is winning a measly 32 games a pleasant surprise? Only when it involves these three words: Porzingis, Porzingis, Porzingis! That is all.

Minnesota Timberwolves, 29-53

FiveThirtyEight preseason prediction: 25-57

Vegas Over/Under: 25.5

This is another debatable one. Obviously, 29 wins is nothing to raise a banner about. But after becoming one of only nine teams to beat the Warriors (and one of only two to beat them at home), it’s fair to say that Wolves fans should feel pretty good about the future of Rookie-of-the-Year lock Karl Anthony-Towns and the rest of the young Minnesota core.

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3. Excusable Disappointment (Teams that performed below expectations, but mostly for unforeseen reasons)

Los Angeles Clippers, 53-29

FiveThirtyEight preseason prediction: 56-26

Vegas Over/Under: 56.5

 

Memphis Grizzlies, 42-40

FiveThirtyEight preseason prediction: 50-32

Vegas Over/Under: 50.5

The Clippers and the Grizzlies lost their stars for extended time, though LA has played well without amateur pugilist Blake Griffin. The disappointment here stems more from the fact that the fourth-seeded Clippers are lost in the West’s no man’s land. Built to win now, they simply can’t compete with the top three teams in the conference’s top three teams, no matter what Charles Barkley says.

Memphis lost their two best players for most of the year and won eight fewer games than predicted. Pretty straightforward and not overwhelmingly compelling explanation, which seems appropriate for them.

Chicago Bulls, 42-40

FiveThirtyEight preseason prediction: 48.5

Vegas Over/Under: 49.5

New Orleans Pelicans, 30-52

FiveThirtyEight preseason prediction: 45-37

Vegas Over/Under: 47.5

New Orleans lost everyone but their star, though it was recently revealed that Anthony Davis star has been playing with an injury for quite some time now. As for Chicago, is Noah still a star? Is Rose? Chicago’s poor season may be less excusable than the others here. It’s getting tough to tell if the best course for the Bulls is to add a star and try to become a legitimate championship contender, or blow it all up and start over.

4. Utter Disappointment (Teams that sucked much more than they should have)

Houston Rockets, 41-41

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FiveThirtyEight preseason prediction: 52-30

Vegas Over/Under: 54.5

Basketball is a team sport. If you hate your teammates, it’s difficult to play well.

Phoenix Suns, 23-59

FiveThirtyEight preseason prediction: 39-43

Vegas Over/Under: 36.5

Phoenix thought Tyson Chandler would make them a better team. FiveThirtyEight and Vegas agreed. They were all wrong. And twins are not to be trusted.

Philadelphia 76ers, 10-72

FiveThirtyeEight preseason prediction: 22-60

Vegas Over/Under: 21.5

Everything that needs be to said has been said.

5. Eh, Close Enough (Teams that 538 didn’t call right on the money, but weren’t that far off)

Cleveland Cavaliers, 57-25

FiveThirtyEight preseason prediction: 63-19

Vegas Over/Under: 56.5

Cleveland wasn’t a disappointment even though they won six games less than FiveThirtyEight predicted. They still got the top spot in an Eastern Conference, a Conference that’s better than it’s been in recent years. But home court was never gonna save them. Not from the Warriors, not from the Spurs, and not from LeBron’s tweets.

Oklahoma City Thunder, 55-27

FiveThirtyEight preseason prediction: 58-24

Vegas Over/Under: 57.5

Oklahoma City has two of the best five players in the league. One of those players missed a few weeks, and, as a result the team won a couple fewer games than predicted. They are still very, very good.

Dallas Mavericks, 42-40

FiveThirtyEight preseason prediction: 38-44

Vegas Over/Under: 38.5

Dirk Nowitzki will never die.

Utah Jazz, 40-42

FiveThirtyEight preseason prediction: 45-37

Vegas Over/Under: 40.5

 

Denver Nuggets, 33-49

FiveThirtyEight preseason prediction: 29-53

Vegas Over/Under: 26.5

Denver was a little better than expected, and Utah was a little bit worse. The development of Jusuf Nurkić, Nikola Jokic, and Will Barton, as well as the charming antics of rookie Emmanual Mudiay should give fans in Colorado some hope. Similarly, Utah’s trip to the lottery before figuring out what kind of player Dante Exum is going to be shouldn’t cause too much worry.

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Sacramento Kings, 33-49

FiveThirtyEight preseason prediction: 38-44

Vegas Over/Under: 30.5

Say what you about the Sacramento Kings. That’s it. Say whatever you want about them. The organization has become so bizarre that anything you make up could very well be true.

Los Angeles Lakers, 17-65

FiveThirtyEight preseason prediction: 22-60

Vegas Over/Under: 29.5

Last and very nearly least, we have the Lakers. Vegas overrated the Lakers, but that’s excusable — public money always pours in on the Lakers no matter what reality says. A 50.5 over/under would have still had Laker fans betting on the over. FiveThirtyEight knew what most basketball fans have known for a while now: Kobe Bryant stopped playing basketball a long time ago. What the internationally renowned poet was doing on NBA basketball courts these past few years, only he knows.

A look at the top NBA draft picks of the past 20 years

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