I did this last year for the Sox and Yankees. I nailed the Sox prediction of 96 wins. The Yankees outperformed my expectations by four games (94 wins).
This season - a new team enters the fray. The Tampa Bay Rays have been a nuisance all season to the traditional powers of the American League East, and for the moment have shown no signs of slowing down. Being an inexperienced team who have never been in a pennant race before, it remains to be seen if they can handle the pressure.
How about the Yankees? Bias or not, they are the team in this stretch that improved themselves the most. Credit Cashman for getting Nady, Marte, and Rodriguez for a bunch of scrub minor leaguers and a shaky middle reliever. However, they did not improve their starting rotation. Wang is gone for the regular season and Hughes is still a few weeks away. Whether or not they can tread water with Pettitte, Mussina, Joba, and slop remains to be seen.
And finally, the Boston Red Sox. Trading away an icon, a former WS MVP, a fan favorite has left many scratching their heads. However, Manny Ramirez was not going to be the key to a potential repeat - the bullpen remains the biggest question. Their starting rotation has been solid (bumps from Buchholz notwithstanding), and they still have the postseason horse, Josh Beckett.
How will the final 50+ games play out? The best place to start would be the home/away splits the rest of the way for each team:
[table]Team|Home Record|Away Record|Home Games Left|Away Games Left
Tampa Bay|43-16|23-28|22|30
New York|36-26|25-24|19|32
Boston|40-16|24-32|25|25[/table]
The Sox have the most home games of all of the three contending teams remaining. The Yankees have the least...but their home/away splits don't seem to affect them as much. The Rays have a lot of road games in September which will assuredly be the most important stretch of their season.