I'm new on Beyond the Box Score, and I had a few thoughts on traditional ERA. ERA is a traditional statistic used mainly for starting pitchers, and it is based on 9 innings of play. That's fine and dandy for starting pitchers, but what about relief pitchers?
My idea for a new statistic is one called Relief ERA, abbreviated rERA. This statistic would alter traditional ERA in the sense that earned runs are multiplied by the average length of each of a reliever's appearance. Relievers usually pitch 1 inning most of the time, but I want to be more accurate and have it "personalized" to an extent for each individual pitcher.
The equation is this: First, find the average length of each appearance of a reliever. For this example, I’m a Braves fan, so I will do Eric O’Flaherty. I divided 73.67 (73.2 IP last year) by 78 (Games) to find EOF’s average length of each of his appearances, and I get 0.9445. Then, I take earned runs (8) and multiply by that average length (not 9 like in regular ERA) and I get 7.5559. Take that number and divide by the total innings pitched (73.67) and I get 0.1026, rounded to the nearest hundredth as 0.10, which is EOF’s rERA.
Jonny Venters’ rERA is 0.21, and Craig Kimbrel’s rERA is 0.23. This stat basically shows the number of earned runs given up per outing. This stat also shows a pattern that proves its validity. EOF’s ERA was 0.98; his rERA at 0.10. Venters’ ERA at 1.84; his rERA at 0.21. Kimbrel’s ERA at 2.10; his rERA at 0.23. It increases just as normal ERA does.
This statistic can help to bridge the gap between traditional statisticians and sabermetric statisticians. This stat involves a simple equation like traditional ERA, but is more relevant and individualistic towards each player like sabermetrics. It simply changes the constant from 9 to an independent variable, the average length of each player's appearance.