Yesterday, Felix Hernandez went 27-up, 27-down against Tampa Bay, becoming just the 23rd pitcher in baseball history to throw a perfect game. Amazingly, this was the sixth perfect game in the last four years, as Felix joins the company of Mark Buehrle, Dallas Braden, Roy Halladay, Philip Humber, and Matt Cain as the newest members of the club.

Back when Cain threw his perfect game in June — striking out 14 games in the process — I looked at where that game ranked in history, and noted that it was in the conversation with Kerry Wood’s 20 strikeout performance and no-hitters from Nolan Ryan and Sandy Koufax as one of the best games in history. While Game Score does a pretty good job of scaling relative performances, however, it doesn’t evaluate for context — park, league, opponent, etc… So, that’s what I set out to do today.

It’s simply more work than I have time for to go through every perfect game in history to evaluate the quality of the opponent, the park the game was played in, and the run environment of the day, but with the help of Jeff Zimmerman, I was able to look at the most recent six. Thanks to the fantastic custom leaderboard feature here on FanGraphs, it is not that difficult to compile the statistics of a specific group of players, like for instance the batters who were matched up against a guy who threw a perfect game. From there, we can look at the relative strength of the batters that each pitcher had to face.

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