(1) ERA 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 and this will deflate his ERA. .
(2) ERA 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.
In reality, pitchers have limited control over both the number of batted balls that drop for hits and sequencing of events. Thus, Defense Independent Pitching Statistics (DIPS) such as FIP, xFIP, tERA and SIERA have been developed to remove some of the noise of ERA. DIPS are based on things that pitchers do control for the most part - walks, hit batsmen, strikeouts, home runs and types of batted balls (ground balls , fly balls, line drives, pop flies).
Because they are based on things that pitchers essentially control, the DIPS metrics are said to be better measures of true talent than ERA. As a result, they are also better than ERA at predicting future performance. However, they only measure a portion of a pitcher's talent and should be used as complements to ERA rather than as replacements.
More and more fans are becoming comfortable with the DIPS theory, but it is still a really difficult concept to get across to the mainstream. If you ever try to explain FIP or any other DIPS statistic to the uninitiated, you will probably find that they are skeptical of a pitching statistic which ignores hits. They are not likely to buy into it even if they realize the limitations of ERA.
So, rather than asking fans to take the big leap from ERA to FIP, why not meet them half way? Instead of removing hit prevention and sequencing in one step, it might be better to remove one factor at a time. Bill James did that with his Component ERA (ERC). Applying the runs created methodology to pitchers, he determined what a pitcher's ERA should have been based on walks, hit batsmen, strikeouts, homers AND hits allowed. I'm going to look at some similar statistics here based on more modern measures such as linear weights and Base Runs.
We often use Weighted On-Base Average (wOBA) to measure overall hitting performance and it can also be used for pitchers. The American League wOBA Against (wOBAA) leaders are shown in Table 1 below. Tigers ace Justin Verlander led the league with a .268 wOBAA in 2012. Teammates Doug Fister (.302) and Max Scherzer (.316) also finished among the top twenty starters.
Table 1: AL Weighted On Base Average Against Leaders, 2012
Team | G | IP | wOBAA | |
Justin Verlander | DET | 33 | 238.1 | .268 |
Jered Weaver | LAA | 30 | 188.2 | .270 |
David Price* | TBR | 31 | 211.0 | .272 |
Felix Hernandez | SEA | 33 | 232.0 | .284 |
Chris Sale* | CHW | 30 | 192.0 | .291 |
CC Sabathia* | NYY | 28 | 200.0 | .292 |
Jake Peavy | CHW | 32 | 219.0 | .295 |
Jarrod Parker | OAK | 29 | 181.1 | .297 |
James Shields | TBR | 33 | 227.2 | .299 |
Yu Darvish | TEX | 29 | 191.1 | .299 |
Doug Fister | DET | 26 | 161.2 | .302 |
Hiroki Kuroda | NYY | 33 | 219.2 | .307 |
C.J. Wilson* | LAA | 34 | 202.1 | .308 |
Jason Vargas* | SEA | 33 | 217.1 | .310 |
Jeremy Hellickson | TBR | 31 | 177.0 | .310 |
Matt Moore* | TBR | 31 | 177.1 | .314 |
Matt Harrison* | TEX | 32 | 213.1 | .315 |
Max Scherzer | DET | 32 | 187.2 | .316 |
Wei-Yin Chen* | BAL | 32 | 192.2 | .317 |
Scott Diamond* | MIN | 27 | 173.0 | .317 |
It's always good to convert to runs allowed when trying to evaluate pitchers, so I'll do that next. The Base Runs measure was created by David Smythe in the early 1990s. It is based on the idea that we can estimate team runs scored if we know the number of base runners, total bases, home runs and the typical score rate (the score rate is the percentage of base runners that score on average. Base Runs also works well for individual pitchers. The complete formula can be found here.
Justin Verlander had 78 Base Runs Against in 238 1/3 innings this year. This means that he should have allowed an estimated 78 runs based on the number of base runners, total bases and home runs he allowed. He allowed 81 actual runs, so runs scored against him at a slightly higher rate than you would expect (although it was pretty close). The small difference could possibly be due to bad defense, unfortunate timing or just bad luck on locations of batted balls.
Verlander had 40 Base Runs Above Average (RAA) which means that he saved the Tigers an estimated 40 runs compared to the average pitcher in the same number of innings. This was the best total in the AL. Note that this number is adjusted for home ballpark (using five-year ballpark factors developed by Brandon Heipp of Walk Like a Sabermetrician).
Table 2: AL Pitching Runs Above Average Leaders
Player | Team | G | IP | Base Runs | RAA |
Justin Verlander | DET | 33 | 238.1 | 78 | 40 |
David Price* | TBR | 31 | 211.0 | 67 | 35 |
Felix Hernandez | SEA | 33 | 232.0 | 79 | 33 |
Jered Weaver | LAA | 30 | 188.2 | 62 | 31 |
Jake Peavy | CHW | 32 | 219.0 | 86 | 23 |
Chris Sale* | CHW | 30 | 192.0 | 73 | 22 |
CC Sabathia* | NYY | 28 | 200.0 | 81 | 18 |
Yu Darvish | TEX | 29 | 191.1 | 77 | 18 |
James Shields | TBR | 33 | 227.2 | 94 | 17 |
Jarrod Parker | OAK | 29 | 181.1 | 72 | 17 |
Hiroki Kuroda | NYY | 33 | 219.2 | 93 | 15 |
Doug Fister | DET | 26 | 161.2 | 68 | 12 |
C.J. Wilson* | LAA | 34 | 202.1 | 88 | 11 |
Matt Harrison* | TEX | 32 | 213.1 | 96 | 9 |
Jason Vargas* | SEA | 33 | 217.1 | 99 | 8 |
Jeremy Hellickson | TBR | 31 | 177.0 | 81 | 6 |
Matt Moore* | TBR | 31 | 177.1 | 81 | 6 |
Scott Diamond* | MIN | 27 | 173.0 | 80 | 6 |
Max Scherzer | DET | 32 | 187.2 | 88 | 5 |
Tommy Milone* | OAK | 31 | 190.0 | 91 | 3 |
Finally, Table 3 shows that Verlander allowed an AL best 2.91 Base Runs per nine innings (BsR9). Again, this is adjusted for ballpark. The BsR9 statistic is not a novel idea as Mr. Heipp has been using Base Runs in this way for a while. About 93% of runs are earned, so you could multiply this result by .93. to put it on the same scale as ERA if you prefer that. Verlander's BsR9 was slightly lower than his actual 3.06 runs allowed per nine innings (RA) which indicates that he may have pitched a little better than his RA (or ERA) suggested.
Table 3: AL Base Runs Per Nine Innings Leaders, 2012
Player | Team | G | IP | BsR9 |
Justin Verlander | DET | 33 | 238.1 | 2.91 |
Jered Weaver | LAA | 30 | 188.2 | 2.97 |
David Price* | TBR | 31 | 211.0 | 2.98 |
Felix Hernandez | SEA | 33 | 232.0 | 3.27 |
Chris Sale* | CHW | 30 | 192.0 | 3.28 |
Jake Peavy | CHW | 32 | 219.0 | 3.37 |
Yu Darvish | TEX | 29 | 191.1 | 3.41 |
CC Sabathia* | NYY | 28 | 200.0 | 3.55 |
Jarrod Parker | OAK | 29 | 181.1 | 3.64 |
Doug Fister | DET | 26 | 161.2 | 3.70 |
Hiroki Kuroda | NYY | 33 | 219.2 | 3.72 |
Matt Harrison* | TEX | 32 | 213.1 | 3.81 |
James Shields | TBR | 33 | 227.2 | 3.88 |
C.J. Wilson* | LAA | 34 | 202.1 | 3.92 |
Max Scherzer | DET | 32 | 187.2 | 4.13 |
Scott Diamond* | MIN | 27 | 173.0 | 4.18 |
Derek Holland* | TEX | 29 | 175.1 | 4.18 |
Josh Beckett | BOS-LAD | 28 | 170.1 | 4.20 |
Clay Buchholz | BOS | 29 | 189.1 | 4.22 |
Wei-Yin Chen* | BAL | 32 | 192.2 | 4.25 |
That Verlander led in all three of these sequence-independent pitching statistics is more fuel for the argument that he deserves his second consecutive Cy Young award.
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