from Amazon
Friday, June 06, 2008
Hardball Times Team Stats
I don’t know when THT rolled out Fangraphs WPA stats, but I like it. They give you the team-level totals. The Angels for example are a total of +6.5 wins (meaning their actual wins minus losses is 13 games… as you can see, the player performances are a perfect match to their teams’ record). That breaks down as -2.0 wins for batting, +4.7 for starters, and +3.7 for relievers.
Fangraphs is likely using a run environment that is too high, meaning it gives too much credit to pitchers. The total for the 30 MLB teams should have batting as exactly 0.0 and starters+relievers as exactly 0.0. Checking now… the total of the 30 MLB teams is -51 wins on offense and obviously +51 on pitching. So, until David A. updated the run environment charts he uses for the win expectancies, you need to mentally add +51 wins per 70,000 or so PA to your hitters (i.e., about +0.1 wins per 200 PA), and remove 51 wins per 16,000 or so IP to your pitchers (about -0.2 wins per 70IP). As you can see, no big deal at the player level so far.
Also note that starters are way behind relievers, as they always are. Relievers get the advantage in that their run environment is being compared against a fixed point (say 4.50 runs per game), when in fact relievers, because they are relievers, should actually be compared to a lower run environment. But, the charts I provided David doesn’t allow for that to be handled. I can do it, but it’s a pain in the butt.
In any case, since you likely want to compare to replacement level, not average, you’ll have to make an adjustment anyway, so you might as well do it after-the-fact, and not in real-time.
Anyway, the reason I happen to discover THT’s WPA charts, is that Rally was talking about the Mariners fielding. It seems that Safeco is always at the center of issues with fielding stats. They’ve got close to the league-low in both infield and outfield fielding. It’s hard to believe that a team with Beltre and Betancourt and Ichiro can be that dismal. Either the other players are so dreadful as to bring them all down, or one or all of these guys aren’t as good as their reps.
At some point, I’ll be looking at Safeco’s PBP data to see if there’s something strange with their data.