Carl Crawford a definite plus for Red Sox 

December, 9, 2010
By signing Carl Crawford, the Red Sox land one of the biggest prizes on the free-agent market, paying what we ought to call the Werth Premium. It's a deal that's on the long side, but at least it was given to a player who's likely to hold his value through the length of the contract.

Crawford will play in 2011 at age 29, meaning the contract takes him through his age 35 season, giving Boston several years of his peak and just a few years of decline, since athletic players who play good defense do seem to age better into their 30s. He's the best defensive left fielder in baseball and a plus-plus runner who adds a lot of value through his baserunning as a high-percentage base stealer. At the plate, he hits right-handed pitching very well and is more than just a pure fastball hitter, but he struggles against lefties, especially if they can spin or sweep a breaking ball away from him.