Expected no-hitters

When Matt Cain threw a Perfect Game for the San Francisco Giants on Thursday, he became the fifth pitcher in the last four years to do so (no, Galarraga’s game doesn’t count). Perfect Games are also No-Hitters, and there have been a startling 22 no-hitters in the past six seasons (here I am including Halladay’s post-season no-hitter two years ago).

Since the end of the Steroid Era in baseball, pitching has been under a resurgence. Last year was called The Year Of The Strikeout by some, and this year is, so far, exceeding last year’s number. In addition, runs per game and hits per inning have been in decline for the past decade, too. But this isn’t just because batters aren’t hitting as hard or fielding has improved. Walks per inning, too, are at their lowest point in 20 years.

Improved pitching means a better chance of No-Hitters and Perfect Games. Does that explain it completely? Is the recent surge in pitching gems a coincidence – in which case we can expect the frequency to revert to the mean – or a result of improving pitching? I started collecting data to answer this question myself (which you can see after the break), but during the course of my research I found an article by Rebecca Sichel, Uri Carl and Bruce Bukiet titled Modeling Perfect Games and No-Hitters in Baseball.