BtB Power Rankings: Through Wednesday, June 17th, 2009

Welcome to our weekly ranking of all the MLB teams!  In this ranking, we use aggregate team hitting, pitching, and fielding statistics--not team wins, losses, runs scored, or runs allowed--to evaluate the performance of teams to date.  You can think of the estimated winning percentage (eW%) below as how we'd expect teams to fall out if we threw teams with these aggregate statistics into one big league and let them battle it out for thousands of games.

The table is sortable if you click in the header.  All data are park-adjusted when possible.  A legend is below the table, followed commentary about five teams: Giants, Reds, Diamondbacks, Angels, and Cubs.  This week, I focus specifically on looking at disparities between these rankings and Pythagorean team records to date.  There is also a table comparing actual vs. expected run scored and run allowed totals, as well as actual vs. expected winning percentages.

BtB Power Rankings: Through June 17, 2009

Offense = wOBA (park-corrected), eRS (estimated runs scored; wRC from FanGraphs, then park adjusted)
Pitching = tRA and tRns are a home-brew version of Graham MacAree's statistic.
Fielding = Fld: average of bUZR (from FanGraphs) and THT's batted balls statistic (converted to runs)
eRA (estimated runs allowed) = Pitching - Fielding
eW%lg = estimated winning percentage within the specific league (AL or NL)
LgAdj = league adjustment (bonus to AL teams, penalty to NL teams, because the AL has superior level of play)
eW% = estimated winning percentage if all teams were in one league (after league adjustment)
Methods provided in more detail in the first post in this series

Team Leaders (asterisks indicate teams improving in specific ranking):

American League
Offense (wOBA): Rays*, Yankees, Red Sox
Pitching (tRA): Royals, White Sox, Red Sox
Fielding (Fld): Rangers, Tigers, Blue Jays*

National League
Offense (wOBA): Phillies, Mets*, Dodgers
Pitching (tRA): Rockies(!)*, Braves, Cubs
Fielding (Fld): Reds*, Brewers, Pirates

"On Paper" Playoff Leaders (asterisks indicate new leaders):

American League: E=Rays*, C=Tigers, W=Angels*, WC=Red Sox*
National League: E=Mets*, C=Brewers*, W=Dodgers, WC=Rockies(!)*

Commentary below the jump!

Given the recent discussions about differences between these rankings and actual records, I thought it would be fun to take a look this week at some teams with the largest absolute differences between expected winning percentage (eW%lg) and Pythagorean record based on actual runs scored and runs allowed totals.  That, after all, is where these rankings are providing additional information about team performance that can't be directly gleaned from, say, THT's excellent teams page.  Let's start with the team that has generated the most controversy thus far...

San Francisco Giants

In the standings, the Giants are in second place in their division (0.523 W%), and are essentially tied with the Mets for second place in the wild card standings.  Furthermore, to date, the Giants have outscored their opponents by a small margin (259-254), which works out to an expected PythagoPat W% of 0.509.  But in these rankings, they come in 29th!  And that's up from dead last in all of our previous rankings.  What's going on?  If we look at all of the hitting events produced by the team thus far, and assign run values to each of them, the Giants' estimated runs scored ( (eRS, after park adjustments) is dead last in baseball: 238 runs.  That's 19 shy of the park-adjusted actual runs scored total, which may suggest that the Giants have been a bit lucky with their offense.  To this end, their clutch rating is the highest in baseball.  It's unlikely that they'll have simliar clutch ratings over the rest of the season.

Based on our version of tRA, as well as our composite fielding estimate, they have been even more lucky in run prevention.  Their estimated runs allowed is 28 runs higher than their actual runs allowed total!  This means that not only have the Giants scored more than expected, they've also allowed fewer runs than expected--all of which indicates that, if they perform at the same level over the rest of the season, they are likely to suffer declines in boht offense and defense.  This is why they are ranked so poorly in our power rankings.

Now, you have to remember, there are many sources of error here than can throw our estimates off.  For example, our two measures of fielding, bUZR and THT's batted-ball stat, are at odds over the Giants' fielding prowess.  bUZR rates the Giants as a +7 run team, whereas THT rates them as a -8 run team.  We split the difference and rate them as essentially an average fielding team.  But if we instead were to go strictly with bUZR, the difference between actual and expected runs allowed shrinks by almost eight runs.  I'm sure other folks could probably find other methodological tweaks that might further push our estimates toward (or away from) the Giants' favor.  But the discussion should be about the methods themselves, not about my apparent bias against the Giants. :) 

Speaking of which, the second most-negatively impacted team happens to be "my" team:

Cincinnati Reds

It's been a fun season (for once) to be a Reds fan, as the Reds have gone through an amazing transformation this year into a pitching and fielding team, and it's paying off: 3 games back from the league-leading Brewers, and with help on the way in Joey Votto and Edwin Encarnacion, both of whom appear on the mend. It's been a rough week (the Royals reversed their slide in last week's rankings by sweeping the Reds--and they didn't even need Grienke to do it), but they're still in a great spot at this point in the season and are very much in the hunt.

Unfortunately, the Reds are similar to the Giants in that the power ranking thinks they've been lucky on both offense and defense.  The Reds' offense started reasonably well, but this month has spiraled towards atrocious.  And unfortunately, our estimates (or rather FanGraphs' estimates, as we're just using their wRC to estimate offense) think they've been lucky by about 13 runs on the season.  Similar, our estimated runs allowed is 22 worse than the actual totals, despite the Reds' league-leading fielding and above-average pitching.  As a fan, I'm rooting for them.  But the power rankings indicate that they've been pretty lucky.

Arizona Diamondbacks

The Diamondbacks have had a frustrating season, with key injuries (especially to Webb), as well as a surprisingly bad offense this side of Justin Upton.  They're currently dead-last in the NL West, fifteen games behind the excellent Dodger ballclub.  But if it's any kind of silver lining, our power rankings think they've been unlucky.  Offensively, there's not much of a story: actual runs scored and expected runs scored are within one run of each other.  But defensively, there's a huge disparity: we estimate that the Dbacks should have allowed 35 fewer runs than they actually have!

Despite the absence of Brandon Webb, The Diamondbacks have had excellent pitching thus far.  We have their staff at a 4.21 tRA (that's on an RA, not ERA scale, so average is ~4.7 runs per game), which is 5th in the National League.  And their fielding has also been above average, an estimated 11 runs above average (bUZR likes them better than THT, but both estimates have them above average).  And yet, even after correcting for their park, the Diamondbacks have actually allowed 4.6 runs per game--right about, or maybe slightly better than average.  Maybe some of that is a matter of leveraging their bullpen differently or something, but my guess is that a lot of what's happening here is just plain and simple bad luck.  As a result, the power rankings rate the Diamondbacks as a 0.500+ team, well above their true W% of 0.424 or their PythagoPat W% of 0.445.

Ok, enough about where there are disparities. Let's talk about a few cases where there are agreements.

California Angels of Anaheim, Los Angeles (or whatever they're called)

The Angels still aren't at full strength, but they've been surging of late, riding a six-game winning streak to close the deficit with Texas to just two games.  And, for the first time this week, they are rated as our on-paper leaders in the AL West, overtaking the Rangers by just one-thousandth of a point.  Time will tell if they can keep it up, but they've had a great week. 

They're also a case where actual records and PythagoPat records agree almost perfectly.  We estimated, after park adjustments, that the Angels should have scored 320 runs.  They've scored 317.  And we estimate that they should have allowed 313 runs.  They've allowed 312.  Expected winning percentage, specific to the AL, is 0.506, whereas PythagoPat's expected winning percentage is 0.512.

The Angels aren't the only match.  Here's another:

Chicago Cubs

The Cubs have had a rough week, losing five of their last six games.  They've fallen out of our on-paper leader in the NL Central this week, are below 0.500, and are 4.5 games out of first place in their division.  But this is again a case where our rankings and PythagoPat are very close, with runs scored estimates aligning perfectly with reality (which is unfortunate for the Cubbies!), and runs allowed estimates falling just five shy of the actual totals.  Expected winning percentage in the NL (eW%lg) for the Cubs is 0.501, PythagoPat is 0.509.

Actual vs Expected Performances

Below are actual vs expected winning percentages, runs scored, and runs allowed.  When a team's ranking deviates substantially from their actual performance (e.g. the Giants), this table will hopefully help you see why.  Runs scored estimates average 10 runs different from actual totals, whereas runs allowed estimates average 14 runs different from actual totals.