The Josh Beckett extension gives the Red Sox rotation security through 2014. Here is where the starters stand in terms of what they have left on their deals counting this season:
John Lackey: Signed through 2014 for $82.5 million.
Josh Beckett: Signed through 2014 for $80 million.
Jon Lester: Signed through 2013 for $28.75 million with a $13 million option for 2014.
Daisuke Matsuzaka: Signed through 2012 for $28 million
Tim Wakefield: Signed through 2011 for $5 million
Meanwhile, Clay Buchholz hasn't reached arbitration yet and they have Casey Kelly, Michael Bowden, Felix Doubront, Stolmy Pimentel, Drake Britton, etc. on the way.
What the Beckett deal does is give the Red Sox the flexibility to use Buchholz or other young starters as trade chips if needed.
Now while this roster of starters is deep, depth can be fleeting. Nobody has any idea for sure what Matsuzaka is any more, Buchholz is still somewhat unproven, Wakefield is 43 and an injury can strike at any time.
But the smartest move in baseball is to get as many good starters as you can under control and the Red Sox have done that. It's a major investment and probably a good one.