His 2.74 ERA is a little less impressive, but we know that ERA is not a good statistic for relief pitchers. One reason is because relievers often enter games with runners on base and give up another pitcher's runs. Conversely, they may leave games with runners on base and get charged for runs that scored due to hits allowed by other relievers.
One alternative to ERA is the Fielding Independent Pitching (FIP) statistic. FIP estimates what a pitcher's ERA should be based on fielding independent statistics - walks, hit batsmen, strikeouts and home runs. FIP is independent of fielders and also the performance of other relievers. Alburquerque currently has a very low 2.22 FIP because of his astronomical strikeout rate and because he has yet to allow a homer.
Weighted Component ERA (WERC) is another ERA estimator which adds hits to everything that FIP includes. Thus, it estimates what a pitcher's ERA should be based on walks, hit batsmen, strikeouts, home runs and hits. Why might WERC be useful for relief pitchers? There is growing evidence that relievers (especially very good ones) have more control over the results of batted balls than starters. The phenomenon has been studied by Lewie Pollis of Wahoo Blues and Dave Studenmund at The Hardball Times among others. It has been found that at least some relievers tend to allow fewer hits on batted balls throughout their careers than most starters.
One theory is that relievers only have to pitch to a few batters per game and can throw their best stuff on every pitch, whereas starters need to pace themselves throughout the game. Therefore, relievers may be able to induce weaker contact than starters. With this in mind, it might make sense to include hits in the evaluation of relievers even if it has been shown that most starters have limited control over batted balls. Thus, WERC might be a good alternative to FIP in evaluating relievers.
Because he has allowed just 4.6 hits per nine innings to go with his large number of strikeouts and zero homers, Alburquerque's WERC is even lower than his FIP. In fact, he leads the American League with a 1.66 WERC. The AL league leaders with 25 or more appearances in 2011 are listed in the table below.
Table 1: AL Reliever WERC Leaders as of July 17, 2011
Player | Team | G | IP | Base Runs/9 IP | WERC |
Al Alburquerque | DET | 28 | 29.2 | 1.79 | 1.66 |
Scott Downs* | LAA | 35 | 31.0 | 1.81 | 1.69 |
David Pauley | SEA | 35 | 48.1 | 1.94 | 1.81 |
Daniel Bard | BOS | 44 | 46.1 | 2.02 | 1.88 |
Koji Uehara | BAL | 40 | 44.0 | 2.19 | 2.04 |
Jesse Crain | CHW | 41 | 41.2 | 2.32 | 2.16 |
Glen Perkins* | MIN | 37 | 35.2 | 2.38 | 2.22 |
Mariano Rivera | NYY | 37 | 35.0 | 2.43 | 2.26 |
Kyle Farnsworth | TBR | 41 | 38.0 | 2.44 | 2.26 |
Joe Smith | CLE | 37 | 34.2 | 2.47 | 2.30 |
Grant Balfour | OAK | 37 | 36.2 | 2.51 | 2.34 |
David Robertson | NYY | 39 | 36.1 | 2.55 | 2.37 |
Vinnie Pestano | CLE | 39 | 35.1 | 2.70 | 2.51 |
Marc Rzepczynski* | TOR | 41 | 37.0 | 2.72 | 2.53 |
Chris Perez | CLE | 37 | 34.1 | 2.74 | 2.55 |
Juan Cruz | TBR | 38 | 34.0 | 2.74 | 2.55 |
Brandon League | SEA | 40 | 37.2 | 2.75 | 2.56 |
Matt Albers | BOS | 31 | 38.0 | 2.77 | 2.58 |
Sergio Santos | CHW | 36 | 42.0 | 2.82 | 2.63 |
Jordan Walden | LAA | 40 | 39.0 | 2.88 | 2.68 |
Other Tiger relievers are listed in Table 2 below. Set-up man Joaquin Benoit (3.48) and closer Jose Valverde (3.51) trail the Amazing Al by a wide margin. Now, one thing that WERC does not do is take into account the game situation in which relievers pitch, but that's a topic for another post. For now, I'll just say that Alburquerque has been close to un-hittable when he has pitched.
Table 2: Tigers Reliever WERC Leaders as of July 17, 2011
Player | G | IP | Base Runs/9 IP | WERC |
Al Alburquerque | 28 | 29.2 | 1.79 | 1.66 |
Joaquin Benoit | 40 | 35.0 | 3.74 | 3.48 |
Jose Valverde | 44 | 41.2 | 3.77 | 3.51 |
Daniel Schlereth* | 29 | 25.2 | 5.57 | 5.18 |
Ryan Perry | 20 | 22.1 | 5.64 | 5.25 |
The raw data used to create the statistics in this post was extracted from Baseball-Reference.
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