Maybe the Yankees read Beyond the Boxscore after all.

In the space we have been lamenting the Yanks’ seeming lack of interest in Mark Teixeira, a player who would immediately improve their offense and defense and is likely to age gracefully. And today comes word that Teixeira will sign an 8-year contract with the Yankees. As such, it’s now fair to say that this has been a good offseason for Brian Cashman.

With Teixeira in tow, the Yankees offense becomes formidable once again, rather than league average. Teixeira instantly improves their infield defense, and allows Nick Swisher to move to the outfield, thus improving the outfield defense too (assuming he’s not in center). The Yankees now can rotate Swisher, Hideki Matsui, Xavier Nady and Johnny Damon between DH and the two corner outfield spots, leaving Melky Cabrera (or Mike Cameron) in center, and thus improving the defense even further.

This is perfect for the Yankees: Nady is best deployed in part-time action, against all lefties and maybe a few righties. Matsui can avoid lefties (not that he’s particularly bad against them anyway), and both he and Damon are significant injury risks. Swisher should rebound from an awful 2008 and can man any outfield position.

The situation gets a bit murkier if it turns out that Jorge Posada can’t be a full-time catcher, but even if that’s the case, Posada can DH some of the time, benching someone like Matsui. The Yankees can try to trade any of these players, but they have no pressing needs and may better off keeping them in case of injury.

While it appears that the Yankees stole Teixeira from the clutches of the Red Sox, the big losers in this situation are the Angels.

While losing Francisco Rodriguez is of relatively little importance to them, losing Teixeira is a huge blow. Their offense was below-average last year and lacks upside once again in 2009, and downgrading from Teixeira to Kendry Morales would be a huge loss. There is still time for the Angels to improve their team, but simply signing Brian Fuentes isn’t the answer. We’re talking about an Angels team whose third-order Pythagorean record was 84-78, and who just lost Mark Teixeira and Francisco Rodriguez. Somewhere, Billy Beane (and Jon Daniels) is smiling.

This is, of course, a big upgrade for the Yankees, but it doesn’t guarantee anything. Last season, the Yankees finished with 91 third-order wins, behind the Blue Jays (92), Rays (97) and Red Sox (102). While the Yankees have undoubtedly improved themselves, they can’t be assured of a playoff spot, let alone a division title. The Rays and Red Sox should once again be very competitive, and while the Yankees signings may have closed the gap it also probably hasn’t created much of a gap between the Yanks and their competitors, either.

The AL East should once again be a dogfight – it’s very possible that this division will contain the three best teams in baseball. The Yankees may be the slight favorites, but at this point the division is way too close to call. Should make for a fun season.