El Guapo's Ghost Rambles on about the Red Sox

ERA needs to go the way of BA

On-base percentage (OBP) is beginning to make its way into the mainstream as a more important statistic than batting average (BA) here in Red Sox Nation. BA is still important just not to the extent that we once believed. ERA should be looked at in a similar manner for a starting pitcher (it should not be included for a reliever but that is another subject).

OBP is an old time statistic. It is not a new wave number like DIPS, GPA, IsoPo, and the like, which likely makes it easier for most media and fans to understand and accept. Starting pitchers need a stat like OBP to lessen the emphasis put on Earned Run Average (ERA).

ERA measures the average number of “earned” runs a pitcher gave up over nine innings. Since preventing runs is the pitcher’s main objective, ERA has become the preferred metric for evaluating a pitcher. Unfortunately, ERA has two major flaws when evaluating a starting pitcher: 1) the Official Scorer decides when an error should be charged to a fielder thereby eliminating the pitcher’s responsibility / being charged with an earned run, and 2) the pitcher is fully responsible for any runners left on base even after his departure from the game; the relief pitcher is not held accountable for any runners on base that precluded his entrance.

For example, the box score of last week’s A’s ass kicking of the Sox had Arroyo giving up nine runs, but six earned in three and one-third. The first inning is standard so moving along to the second.

Below is the espn.com game log for the top of the second.

OAKLAND 2ND
-Top of the 2nd inning
-B Crosby struck out swinging.
-M Scutaro safe at first on error by shortstop P Reese.
-M Kotsay flied out to right.
-E Byrnes doubled to left, M Scutaro scored.
-E Chavez homered to left, E Byrnes scored.
-J Dye struck out swinging.

3 runs, 2 hits, 1 error

Pokey Reese makes an error leading to a runner on first. Reese’s error pardons Arroyo of three runs. The logic beyond the three runs being unearned is that Kotsay’s fly out would have been the third out ending the inning. Byrnes and Chavez would not have come up with ducks on the pond. Staying in that dream world, Byrnes leads off the third. If he and Chavez do the same damage in the third as they did in the real second, the pair would produce two runs instead of three. The logic relieving Arroyo of responsibility is not consistent. Arroyo should have been charged with two runs in the second instead of none.

The other problem with ERA is evident in the fourth inning.

OAKLAND 4TH
-Top of the 4th inning
-B Crosby doubled to left center.
-M Scutaro doubled to deep center, B Crosby scored.
-M Kotsay grounded out to first, M Scutaro to third.
-E Byrnes doubled to left, M Scutaro scored.
-J Brown relieved B Arroyo.
-E Chavez walked.
-J Dye hit a ground rule double to deep center, E Byrnes scored, E Chavez to third.
-S Hatteberg homered to right, E Chavez and J Dye scored.
-E Durazo singled to center.
-A Melhuse flied out to left.
-B Crosby flied out to center.

6 runs, 6 hits, 0 errors

Brown relieves Arroyo with Byrnes on second with one out. Brown walks Chavez, and then Dye hits a double scoring both runners. Arroyo is charged with the run scored by Byrnes and Brown’s ERA will increase due to Chavez crossing the plate. Even though Brown served up the hit that drove in Byrnes, Arroyo and Brown are hit with an earned run apiece. Well that is not fair. Brown had more impact on Byrnes scoring than Arroyo. They should not be charged with the same number of runs. The number of outs and the inherited runner(s) location should be factored in when determining accountability. ERA does no such calculation.

It is likely that some new statistic accounts for ERA’s faults but most people are not receptive to new ideas and change. Hence, runs per nine innings (RA/9) should be posted along with ERA when a pitcher enters the game. It is simple; the public is familiar with it and RA/9 will help alleviate one of ERA’s flaws. RA/9 will account for all runs a pitcher gives up regardless of the number of errors committed. Over the past two years, a number of the best starting pitchers have a RA/9 of more than .5 runs over their ERA. Over 200 innings, the .5 translates into 10 runs; it is significant. Like OBP, RA/9 does not tell the entire story about a player’s performance but it is better than ERA. Baby steps in the right direction are…well, better than nothing.