"On Paper" Leaders
This Week's Breakdown: The Boston Red Sox
Lots of movement this week in the rankings. The Giants surged and secured the second-highest ranking of any NL club, behind only their division rival Padres. My Reds had a nice week, rising up to the 19th slot and posting just shy of a 0.500 component winning percentage. The Rangers have almost caught the Athletics, and the Brewers have almost caught the Cardinals...
This week, however, I think the biggest story is a team that doesn't yet figure in the "on paper" leaders: the Red Sox. After a disappointing month of April, the Red Sox surged last week in the rankings, gaining 52 TPI points and eight spots in the power rankings. While they are still 5.5 games back in reality, the power rankings show their team performance to be just a hair shy of the Rays to this point in the season, and fourth-best overall among all teams.
Here's the interesting thing about the Red Sox: their Pythagorean winning % is .484, and yet we have their component winning % at .580. That's an enormous disparity. What's happening? First, their expected runs scored, based on their underlying statistics, is 10 greater than their actual total. The Red Sox rank second in the AL (behind the Rays) in park-adjusted wOBA, but this hasn't translated into quite the number of runs you would expect thus far.
Second, and more significantly, the Red Sox have allowed 24 more runs than expected. That's a large total this early in the season. What's happening? Their ERA as a team is 4.95, compared to an FIP of 4.46 and an xFIP of 4.43. We might expect to see this on a team with bad fielding, but that's not what the Red Sox are: they rate as +7 runs in fielding (note: just last week, their fielding rated -6 runs, so the latest UZR & DRS updates showed a large reversal here). It could also be their quirky park having an effect, but last year in the same park, the power rankings had Boston allowing 23 fewer runs than expected. The primary remaining explanation is bad "luck": bloop hits, bunched up walks & hits, etc. A major victim of this appears to be Josh Beckett: his 4.36 xFIP is well below his standards, but it's a far cry better than his 7.46 ERA.
Given these data, the indication is that the Red Sox have played better than their record would indicate. Frankly, given how well they projected coming into the season, I think this has to be considered an unsurprising finding. There is a lot of panic in Red Sox nation right now, and 5.5 games is a substantial deficit against teams with comparable talent levels...but it's May. A lot can happen between now and then end of the season. They're not out of this yet.
Converting Runs to Wins
RS = Actual Runs Scored, after a park adjustment
eRS = Estimated Runs Scored, after park adjustment (see "Offense" table below)
RA = Actual Runs Allowed, after a park adjustment
eRA = Estimated Runs Allowed, after park adjustments (see "Defense" 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 adjustment, click in the header and sort by this column.
LgAdj = League adjustment, based on differences in league quality (justification here and here).
TPI = Team Performance Index, a hypothetical winning % based on component estimates of runs scored and runs allowed after the league adjustment.
Team Offenses and Defenses
RS = Actual Runs Scored
eRS = Estimated Runs Scored: wRC + EqBRR
wOBA = The Book's statistic, but park adjusted, and using data from both wRC and EqBRR
OBP = On Base Percentage (Times on Base / Plate Appearances)
SLG = Slugging Percentage (Total Bases / At Bats)
wRC = From FanGraphs, with baserunning removed, after park adjustments
EqBRR = Dan Fox's composite baserunning statistics from Baseball Prospectus, minus stolen bases since they are included in wRC.
Clutch = "Clutchiness" measure from fangraphs; difference between actual WPA and expected WPA based on component statistics. We report this in runs.
RA = Actual Runs Allowed, after park adjustment
eRA = Estimated Runs Allowed: tRuns - Field - Catch
ERA = Straight-up Earned Run Average
FIP = Fielding-Independent Runs, based strictly on K-, BB-, and HR-rates.
xFIP = Experimental 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.
xFIPrns = Pitching Runs Allowed, based on xFIP
Field = The average of team UZR and team DRS (minus rSB since I calculate catcher fielding separately).
Catch = Catcher Fielding Runs, based on SB's, CS's, WP's, PB's, E's, and this year catcher interference. The 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 precision.
BABIP = Batting Average on Balls In Play. Fluctuates at the team level with fielding, although chance events can have effects as well.