On Paper Playoff Leaders
This Week's Feature: The Chicago White Sox
The ChiSox didn't move a lot this week in the rankings, but they currently do sit atop the actual AL Central despite trailing the Twins significantly in the power rankings. Why the disparity?
White Sox fans would be quick to point out that their actual winning percentage (.566) is very close to their Pythagorean record (.557). However, our estimated component winning percentage is substantially lower, at .522. What gives?
The answer comes on both offense and defense. On offense, we estimate that the White Sox "should have" scored 19 fewer runs than they actually have. This is a fairly average offensive team. They have some hitters having excellent years--Konerko, Rios, and Quentin (when healthy). But they also are starting players who have either severely underperformed (e.g. Gordan Beckham, .289 wOBA, -11 wRAA), or just aren't very good hitters at this point in their careers (Pierzynski .273 wOBA, Pierre .305 wOBA). They've average on the basepaths as well.
On defense, we estimate that they've allowed 15 fewer runs than expected. Again, not a huge difference, but it again moves our estimated w% down. Pitching-wise, there's a lot of disagreement here in how good these guys are. I haven't checked carefully, but the gap between their park-adjusted FIP (3.54 FIP) and their xFIP (4.13) is about as enormous as it comes. The White Sox play in a home run friendly park, and yet amazingly, their HR/FB% is the best in baseball. That hints at some HR/FB "skill" on this team, though it's hard to say for sure. This is why I like the change we instituted last week: we split the difference between FIP and xFIP to calculate our pitcher runs allowed estimate. That average "FIP" (3.84) is very close to the team's actual ERA (3.91)...which means that the gap here could be said to come down to fielding.
Fielding-wise, the team rates as below-average (-10 runs by my methods). I think it's a pretty solid estimate, too, because we're getting these measures across the board: UZR and DRS both have them at -16 runs, while a fielding estimate based on FIP and Base Runs puts them at -5 runs. Catching has been plus thus far (+4 runs), but that's the only good news. It's not the worst fielding team in baseball, but it doesn't look particularly strong.
So what we have here is a modest bit of overproduction on both offense and pitching/fielding, which adds up to a fairly big gap between actual vs. expected team performance. On top of all of that, the White Sox also have had a fairly weak schedule: we estimate their average opponent cW% at .487, which is the third easiest in the AL. Adjusting for this weaker competition pulls their cW% down from .522 to just .502. As a result, despite leading the AL Central in reality, we rank them as being significantly behind the second place Minnesota Twins.
Under the Hood
Converting Runs to Wins
RS = Actual Runs Scored, after a park adjustment
eRS = Estimated Runs Scored, after park adjustment (see table below)
RA = Actual Runs Allowed, after a park adjustment
eRA = Estimated Runs Allowed, after park adjustments (see table below)
W% = Actual Winning Percentage
pW% = PythagenPat Winning Percentage, based on actual runs scored and run allowed totals
cW% = Component Winning Percentage, using estimated runs scored and estimated runs allowed totals. If you don't like the league adjustments or strength of schedule adjustments, click in the header and sort by this column to get an "unsullied" ranking.
SoS = Strength of Schedule. This is an iterative weighted average of the component-based winning percentages of a team's opponents. Described in this post.
cW%s = Schedule-adjusted Component Winning Percentage. Calculated by applying SoS to cW% with the log5 method, as described in this post.
xTW = Extrapolated wins. Based on current real wins to date, and extrapolated wins over the rest of the season. Extrapolations are based on an average of cW% and cW%s, as justified in this post.
LgQ = League Quality. The AL has superior talent to the NL (justification here and here, and modified most recently here). The number shown is an estimated true talent level (in winning percentage) of the two leagues were they to be able to play one other for a large number of games. It's based on the last two years of interleague, with a small adjustment toward 0.500 to account for the fact that the leagues do play one another and thus have already had a small effect on one another's performance.
TPI = Team Performance Index, a hypothetical winning % based on cW%s, after adjustment for league quality. Think of this as the W% we'd expect teams to have if they were all in one big league and were allowed to play 10,000 games vs. every team.
Team Offenses and Defenses
RS = Actual Runs Scored
eRS = Estimated Runs Scored: HitRns + EqBRR
wOBA = The Book's statistic, but park adjusted, and using data from both HitRns and EqBRR
OBP = On Base Percentage (Times on Base / Plate Appearances)
SLG = Slugging Percentage (Total Bases / At Bats)
HitRns = Base Runs-estimated runs scored, ignoring all base running, using the equation in this post.
EqBRR = Dan Fox's composite baserunning statistics from Baseball Prospectus, minus stolen bases since they are included in wRC.
RA = Actual Runs Allowed, after park adjustment
eRA = Estimated Runs Allowed: PitRns - Field
ERA = Straight-up Earned Run Average
FIP* = Fielding-Independent Runs, based strictly on K-, BB-, and HR-rates. HR/FB rates are park adjusted using these park factors.
xFIP = Expected Fielding-Independent Runs from FanGraphs. Like FIP, but with HR/Outfield Fly Ball rates regressed completely to league average. xFIP is as predictive as any other DIPS-like stat.
PitRns = Pitching Runs Allowed, the expected runs allowed based on the average of FIP and xFIP. Described in this post.
Field = Described in this post. It is essentially an average of team UZR, DRS (minus rSB since I calculate catcher fielding separately), and BsRFld. BsRFld is just difference between FIP-based runs allowed and park-adjusted Base Runs, and is a less direct approach of measuring fielding. The fielding number also includes a catcher fielding statistic, based on SB's, CS's, WP's, PB's, E's, and this year catcher interference. The catching methods are essentially those described here. But I'm using B-Ref data this year, and so there are slight tweaks to the methodology, generally in ways that should lead to greater accuracy. If you want to know, feel free to ask!
BABIP = Batting Average on Balls In Play. Fluctuates at the team level with fielding, although park effects and chance events can have effects as well.