As an example, Tigers right hander Max Scherzer has allowed 54 walks and 22 home runs, has hit 3 batters and has 195 strikeouts in 154 2/3 innings this year. This translates into a FIP ERA of 3.57 which is the ERA a pitcher "should" have given those numbers. This is more than a half run lower than his actual ERA of 4.13.
A pitcher who allows 3.57 earned runs per nine innings over 154 2/3 innings theoretically adds about three (3.2 WAR) wins above what a "replacement" pitcher would contribute. On the other had, if Wins was based on runs allowed per nine innings (RA9), Scherzer would be a little more than two wins (2.4 RA9-Wins) above a replacement-level pitcher. That's a fairly substantial difference and such discrepancies happen often, which is one of the sources of skepticism regarding WAR.
There are two main reasons why WAR (based on FIP) can be different from RA9-Wins:
- RA9-Wins gives pitchers full credit/blame for results of batted balls in play despite the fact that they share that responsibility with fielders. For example, a pitcher with a strong defense behind him will tend to give up fewer hits (and thus fewer runs) than if he had a poor defense behind him. fWAR, on the other hand gives a pitcher zero responsibility for what happens on balls in play.
- RA9-Wins gives pitchers full responsibility for sequencing or timing of events, that is, it assumes that they can control when they give up hits and walks. For example, if a pitcher pitches extraordinarily well with runners in scoring position in a given year, he will have a lower ERA than if he had a typical year in those situations. Additionally, a pitcher who tends to bunch base runners together in single innings will have a higher ERA than if he had a typical year distributing base runners more evenly. WAR gives a pitcher zero credit/discredit for sequencing.
However, FanGraphs is now putting RA9-Wins, WAR and numbers that explain the difference between the two side by side:
RA9-Wins = Wins for a pitcher based on total runs scored while he is pitching
WAR = Wins for a pitcher based on SO, BB, HBP, HR
FDP-Wins = RA9-Wins minus WAR = Wins not accounted for by SO, BB, HBP, HR
BIP-Wins = Wins contributed by outcomes of balls in play
LOB-Wins = Wins contributed by sequencing of events or runners left on base.
Scherzer has the following numbers so far in 2012:
RA9-Wins = 2.4
WAR = 3.2
FDP-Wins = -0.8
BIP-Wins = -1.7
LOB-Wins = 1.0
The negative number for BIP-Wins tells us that Scherzer has not had good results on balls in play. This is also seen in his unusually high .347 Batting Average on Balls in Play (BABIP). This could be a result of poor fielding support (we know the Tigers don't offer much of that) or bad luck on balls in play. We don't want to assume that none of it his his fault though. While pitchers do share the responsibility of results of batted ball with fielders, some pitchers do get hit harder than others. These are questions that can't be fully answered until complete data on speed, distance and trajectory of batted balls become freely available.
Scherzer's positive number for LOB-Wins reveals that the runners he does allow have not been scoring at a high rate. How much of this is skill as opposed to good fortune is not known. We do know that his 76% LOB% is higher than his career mark of 73%, so perhaps he has been a bit lucky in that respect this year.
These new statistics certainly don't answer all the questions about pitching, but it's good to see runs allowed, WAR, results of balls in play and runners left on base all in the same unit (wins) and all on the same page. I'll be examining these numbers for other Tigers pitchers in future posts.