I think I figured out a good Cy Young formula

Posted By on September 22, 2010 1:35 pm

As you know, I have an NL Cy Young vote this year. As you also know, the two numbers I think are the most important are ERA¬† and opponents OBP. They measure how well a pitcher does his two most important jobs: prevent runs and get outs. I’ve always kind of struggled with a couple other elements, though: ballparks and innings.

I know that all ERAs are not created equal, because some guys pitch in Denver and some guys pitch in San Diego. I also know that innings pitched matters because the more innings you pitch, the harder it is to keep your ERA down. (More innings also makes you more valuable to your team, but I’m not as interested in that side of it. I’m not trying to figure out who the most valuable pitcher is. It’s the pitcher who pitched the best.)

My old system would be to look at the top pitchers and see where they ranked in the two categories, and give them points based on their rankings. But that’s not so great either, because if one guy has a 2.30 ERA and the next-closest is 2.60, he needs to get credit for more than just one spot in the rankings. By the same token, the difference between 2.30 and 2.32 shouldn’t count as much.

So, here’s how I have solved these problems.

First, I’m going to use ERA+, instead of ERA, because that takes a player’s home park into account. I don’t know how it does, but it does. It also normalizes everyone’s ERA to a positive whole number, with 100 being average, so it’s easier to compare.

As for the innings, I decided, somewhat arbitrarily, that every inning pitched over 200 was worth half a point in ERA+. And pitchers who were under 200 would lose points. For example, a guy with an ERA+ of 140 who pitched 220 innings would get an innings-adjusted ERA+ (iERA+) of 150. A guy with an ERA+ of 140 who pitched only 180 innings would get an iERA+ of 130. That seems reasonable.

Next, I took the opponents OBP and compared them with the league average, giving a guy one point for every point better than the average. The NL OBP is .326, so a pitcher who allowed an OBP of .290 would get 36 points. I like this because it’s automatically weighted less than ERA because of the numbers, which I think is appropriate.

Now, all you do is add up the points and see who has the most. Voila!

I should also point out that I don’t plan to simply plug in these numbers and then do my ballot in exactly that order. I will reserve the right to tweak the order based on other factors if two guys end up very close by the numbers.

(There is also the closer factor. My formula doesn’t work for guys like Heath Bell and Brian Wilson, both of whom I think would merit some consideration for the bottom of the ballot. I may decide to throw the better of those two, which I haven’t yet determined, on as No. 5, depending on who I come up with as the potential fifth-place starter by my calculations.)

I can’t tell you how all that looks right now, because we’re too close to the end of the season, and it’s likely to be my final ballot, which I can’t reveal. Of course, nothing is stopping you from doing the math yourself.


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