Statistically Regressing the Phillies’ Offense
EDIT: Petti noticed an error in his calculator. He e-mailed me the updated numbers. As such, the post has been edited to reflect the changes.
At Beyond the Box Score, Bill Petti (@BillPetti) did some number-crunching, looking at the actual production (in terms of wOBA) from baseball’s best and worst hitters and comparing it to a regressed version, using each hitter’s numbers over the past three years. Petti described his process:
To gain some perspective on the early returns this season I decided to regress all batters with >=40 plate appearances by their 3-year average batting average on balls in play (BABIP) and their 3-year average HR/FB rate. The chart above presents the top-15 and bottom-15 batters in terms of the difference between their actual wOBA this year and what we would expect given their 3-year averages in BABIP and HR/FB.
Petti made his calculator public, so I downloaded it and ran the numbers for the Phillies. Below are the results.
In graph form (click to enlarge):
Five of the eight hitters come out looking better after the regression. Ibanez goes from a .231 wOBA to .293, but that is still well below average (around .315). Howard had a .046 point regression up to .408, and Rollins went up .015 to .321. Ruiz jumped 24 points to .024 while Valdez had barely any change at all, moving only three points.
Polanco fell the hardest, from .415 to .347, an 68-point plunge. Victorino and Francisco were hit for 27 and 9 points to .336 and .328 respectively.
It’s not the most encouraging analysis, for sure, but things could be worse. The offense hasn’t been good lately and there aren’t any excuses for that, not even bad luck. That won’t change by any significant margin unless the Phillies get Chase Utley back and at his previous level of production, Domonic Brown makes a speedy rebound from a broken hamate bone, or if they get creative as Eric Seidman hypothesizes at Brotherly Glove.