There is no accurate strength-of-schedule adjustment anywhere on the web; BP's (as I've noted before) underestimates the effects of competitive balance profundly (by looking at only opponents' SOS rather than schedule-adjusted opponents SOS -- and in fact you need to repeat (nest) the adjustment about 20 times).
Here are adjusted Pythagorean standings based on actual RS and RA through the end of Sunday. The Karma adjustment is positive for bad karma and negative for good karma (that is, it's the change in the number of wins if they had played to their Pyth percentage, just as the SoS is the change in wins if they had had an average schedule).
And here is the same thing based on EqRS and EqRA, that is, the team's cumulative hitting and pitching stats and the number of wins you'd expect if they had tranlated into RS andd RA with neutral karma. I think the SoS adjustments in this version are the best to use; there's no reason to think that the NL has a real advantage in turning offensive and defensive events into more RS and fewer RA than the AL does despite being the inferior league talent-wise.
You see that four of the five best teams in MLB are in the AL East. Last year, it was the top four.
Average SoS adjustment by division:
AL East: 2.5
Al Central: 1.8
Al West: 1.3
Nl East: -0.9
NL West: -1.5
NL Central: -2.0
To answer the question "how would team X fare in division Y," take the team's own SoS and add it to the division adjustment. For example, the Sox would be 44-19 or 43-20 if they were in the NL Central.
The overall difference between the leagues, 3.4 wins after a bit more than a third of a season, is consistent with last year, when it was 10.3 wins over the full season.
Edited by Eric Van, 16 June 2009 - 05:58 AM.