Are No-Hitters On the Rise? No. Just the % of CGs.

Last night, Jered Weaver threw the 274th no-hitter in baseball history — or so the stories say. There have been two no-hitters so far this year, and ten so far in this young decade. Half of them came in 2010, the year whose no-hit frequency led some to dub it “The Year of the Pitcher.”

And, indeed, the five regular-season no-hitters thrown in 2010 (along with a sixth, by Roy Halladay, in the playoffs) mark it as one of the no-hittiest years in history. The five regular season no-nos tie it for third place, with 1962, 1968, 1973, and 1991, and the six overall tie it for second place with 1969. (Of course, many will remember that there almost was — and should have been — a seventh.) But the most of all were thrown in 1990: eight overall. The frequency of no-hitters per year hasn’t increased, except with respect to the historically anomalous 2000’s.

Data here and throughout compiled from baseball-reference play index and MLB.com’s no-hitter registry.
If anything, the graph of no-hitters by year looks something like a letter M, with modes in the early 1900’s and the late 1960s, which is what you’d expect: the deadball era, and the neo-deadball era. The picture looks about the same when you include one-hitters and the postseason. (Box score data is spotty until 1918, so that’s when these data begin.) So the list of no-hitters and one-hitters, including the postseason, looks sort of like a normal curve centered around the late ’60s.

How many have there been overall? Depends on where you look. Most of the Weaver stories placed it at 274. According to ESPN’s no-hit registry, there have been 267 no-hitters, 258 of which have been complete games thrown by the starting pitcher. (MLB.com’s no-hit registry noted a couple that ESPN missed — perfect games by Monte Ward and Lee Richmond in 1880, but appears to miss many others, so I opted to combine ESPN with baseball-reference.)

The number of no-hitters hasn’t increased. It’s more or less remained around the historical norm. But the number of complete games, of course, has drastically decreased. (The increase in the 1960s is largely a product of the expansion of the schedule from 154 to 162 games.)

It certainly seems like throwing a no-hitter increases a pitcher’s chances of staying in the game. This was particularly apparent in the postgame comments after Edwin Jackson’s 149-pitch no-hitter in 2010. “We talked every inning after about the sixth because I was checking on him,” said then-Diamondbacks manager AJ Hinch. “It’s such a complicated situation with the game in the balance and him chasing a no-hitter.” In just the last two decades, the proportion of all complete games that were no-hitters has zoomed upwards from its historical rate, which was under one percent for most of the previous century.

This year has been insane, of course. There have been just 15 complete games, two of which have been no-hitters. The ten no-hitters this decade mean that the 2010’s are almost certain to pass the meager tally of the previous decade; there were just 15 no-nos is the 2000’s, and just 15 in the 1980’s. As a matter of fact, we’re on pace for 46 no-hitters this decade, which would be the most ever. The current high-water mark is the 34 no-hitters pitched during the 1960’s, including four by Sandy Koufax, of course. (There were 30 in the 1990’s, partly aided by the four expansion teams added in 1993 and 1998.)

Jered Weaver’s a terrific pitcher, and he’s the first Weaver to enter his name into the no-hitter history books, let alone the first Jered. (His big brother Jeff pitched a complete game one-hitter in 2002, as his Tigers beat the Indians 2-0. Jeff needed 125 pitches to do that; Jered took just 121 pitches last night.) The 29-year old Weaver was the Cy Young runnerup last year, and he’s currently leading the league in ERA and strikeouts, and tied for second in wins. If he brings home the pitching triple crown, it will be hard to deny him the Cy. But modern baseball has also made it increasingly hard for pitchers to finish their own games, because of the emphasis on pitch counts. The next time he wants to throw a complete game shutout, he may want to make sure not to allow any hits.