By: Steven Silverman
After having the good fortune to attend Josh Beckett’s no-hitter against the Phillies on May 25, 2014, I started doing some reading about no-hitters out of curiosity. Eventually, I came across this article by Bill James on the likelihood of pitchers throwing a no-hitter. The natural extension was to update the standings for perfect games.
I utilized a similar method to James’s, except I calculated the “out percentage” as
(3*IP) / ((3*IP)+H+BB+HBP))
factoring in other outcomes that the pitcher is responsible for. Since I don’t include errors, defensive interference, or reaching on a dropped third strike, the end probability will be a small percentage higher than the actual probability. Think of it instead as how “deserving” the pitcher was of a perfect game. Taking the out percentage and raising it to the 27th gives us the chance of a perfect game in any particular start, and then multiply by career starts to get a final expectation.
Without further ado, here are the top 32 pitchers, sorted by expected perfect games thrown:
|Old Hoss Radbourn||503||0.0735||0|
Note that of the top 32, only 6 actually did throw perfect games, with several others coming very close (most notably Pedro Martinez, who threw 9 perfect innings in a 0-0 game before giving up a hit in the 10th). The total expected perfect games is just under 3, with the discrepancy mostly arising from the tiny sample size: a perfect game is such a “lightning-in-the-bottle” incident that it’s challenging to get an accurate prediction. Overall, though, the rankings work pretty well- the bias toward 19th-century pitchers notwithstanding.
Below are the expectations for the 23 pitchers that have thrown perfect games, with the more shocking ones like Charlie Robertson and Philip Humber low on the list:
I created the “Expectation/100” column to show how likely a pitcher was to pitch a perfect game over 100 starts. This serves as a normalization of sorts, and it’s clear that Joss and Ward had by far the best per-game chance of a “perfecto.” In fact, Joss comes out on top of all pitchers with at least 50 starts. Joss’s abbreviated career (nine years, cut tragically short by tubercular meningitis in 1911) knocked him down the unadjusted list.
There’s nothing else to this analysis, really—it’s just a nice stat to think about.
Here’s to hoping you see a perfect game your next time at the ballpark.