Overperforming/Underperforming Baseball Teams According to Pythagorean Expectation

In this blog, I have decided to look at which baseball teams records that reflect their overall performance, and which teams have records that don't.

Using the Pythagorean Expectation formula used by Bill James (win pct=RS^2/(RS^2+RA^2)), I determined the expected win percentage of all MLB teams. However, I replaced the coefficient of 2 with 1.81, which is supposedly more accurate. Understand that while the Pythagorean Expectation is quite accurate, it doesn't take into account good managing and clutch performances. Still, it is a useful and telling statistic for the most part. It could help to answer questions such as if the Rays are the real deal or not.
Here is the data:

AL East	RS	RA	PCT	P1.81	Diff
Tampa Bay	639	546	0.618	0.571	0.047
Boston	729	580	0.587	0.602	-0.02
NYY	671	630	0.536	0.528	0.008
Toronto	603	531	0.518	0.557	-0.04
Baltimore	704	739	0.457	0.478	-0.02
AL Central	RS	RA	PCT	P1.81	Diff
ChiSox	696	611	0.558	0.559	-0
Minnesota	703	623	0.558	0.554	0.004
Cleveland	669	629	0.489	0.528	-0.04
Detroit	695	703	0.478	0.495	-0.02
KC	562	686	0.423	0.411	0.012
AL West	RS	RA	PCT	P1.81	Diff
LA Angels	633	573	0.613	0.545	0.068
Texas	768	836	0.486	0.462	0.024
Oakland	533	574	0.457	0.467	-0.01
Seattle	581	690	0.391	0.423	-0.03
NL East	RS	RA	PCT	P1.81	Diff
NY Mets	684	604	0.561	0.556	0.005
Philly	669	576	0.547	0.567	-0.02
Florida	647	681	0.504	0.477	0.027
ATL	639	669	0.432	0.479	-0.05
Washington	535	686	0.381	0.389	-0.01
NL Central	RS	RA	PCT	P1.81	Diff
ChiCubs	750	566	0.612	0.625	-0.01
Milwaukee	663	577	0.58	0.563	0.017
St. Louis	673	621	0.54	0.536	0.004
Houston	624	653	0.525	0.479	0.046
Cincinnati	588	686	0.442	0.431	0.011
Pittsburgh	618	754	0.423	0.411	0.012
NL West	RS	RA	PCT	P1.81	Diff
Arizona	634	609	0.507	0.518	-0.01
LAD	578	568	0.496	0.508	-0.01
Colorado	656	708	0.471	0.466	0.005
SanFran	530	649	0.428	0.409	0.019
San Diego	533	649	0.384	0.412	-0.03

As you can see, most of the actual winning percentages are extremely close to the Pythagorean Expectation. However, a few things stick out to me.
1. LA Angels Overperforming--The team that differs the most from its actual winning percentage are the Angels. According to the theory, they are actually only the 5th best baseball team in the AL despite having the 2nd best record. The cause for this is probably a combination of a few things: great managing by Mike Scioscia, winning a lot of close games (K-Rod has had 59 save opportunities), timely hitting, and getting lucky. The Angels are a good team with playoff experience, but don't be surprised if they fall quickly in the postseason.

2. Rays the Real Deal, Kind of--Are the Devil Rays truly a playoff caliber team this year? Yes. Are they the best team in the AL (currently they own the best record)? No. Behind the Angels, they are the 2nd most overperforming squard in the MLB, and haven't been playing as well as the Red Sox (who are slightly underperforming). Unless David Price provides a major spark for the Rays this month, I can't see them getting past the much more experienced, underperforming Red Sox team.
3. Cubbies are Heavy Favorites in the NL--The Cubs are even slightly underperforming, while the Brewers are overperforming. Their Pythagorean (with 1.81 exponent) Win % is >0.06 pts ahead of the Brewers. This should be the year, but of course Bill James doesn't take curses into account.
Conclusion--Admittedly, this analysis didn't show anything really eye-opening, but I found it interesting nonetheless. The postseason is short, teams get hot, players get injured, and there is a lot of natural deviation, so it's impossible to have a 100% positive pick on which team will win the pennant or a series. Most of the time, the best team in the MLB won't win the World Series.

Natural deviation has never been as apparent as last year, when the Diamondbacks scored less runs than they allowed but had the best record in the NL and swept the cubs in the divisional round.

Just adding this in as an annoyed Yankees fan: The firing of Joe Torre was a ridiculously ignorant decision. Fact is, you can't completely evaluate how good a team or a manager is by the results in a short postseason. A manager could easily lose despite making smart, educated moves, and that is what happened to Joe Torre. There is too much deviation. Bringing a team to the playoffs that many years in a row is an amazing accomplishment. If you're going to fire somebody based on postseason performance, evaluate their decisions and their preparation, but not their results.