Could 2021 Be the Year of the No-Hitter?

I was unwinding on Friday after a long week of work when I got an alert from MLB that Wade Miley was throwing a no-hitter against Cleveland. I blinked my eyes a couple of times in disbelief before putting the game on, but as I was watching Miley complete his no-hitter, my alerts went off again: Sean Manaea had a perfect game in progress in Oakland. He ended up losing it when Randy Arozarena walked in the seventh and his no-hitter when Mike Brosseau led off the eighth with a double, but if your head is spinning a bit from all the alerts, you are not alone. We are barely five weeks into the 2021 season, and we’ve already seen four no-hitters (five, if you count Madison Bumgarner’s seven-inning no-no, which MLB officially doesn’t). As fun as it has been to follow the action this season, something historically anomalous is afoot.

Let’s start with the raw numbers. There are only 21 full MLB seasons with four or more no-hitters since 1901, and the only season that saw more than four no-hitters happen before May 15 is 1917, when five took place (all before May 6). That season ended with six no-hitters and a tie for the highest percentage of no-hitters per game played — until now.

The existing record of no-hitters as a percent of total games is at 0.48%, which has happened twice in MLB history, but it’s unlikely many of us were around for those 1908 and 1917 seasons. The vaunted 1968 “Year of the Pitcher” season that resulted in the mound being lowered five inches doesn’t even crack the top-10 list in terms of no-hitters as a percent of total games. Here are the top 20 seasons for no-hitters as a percent of total games, including 2021 data through May 9:

No-hitters are an atypical event: Since 1901, only 0.13% of baseball games have resulted in one. On a season-by-season basis, you are more likely to see a year with zero no-hitters than one with five or more.

Even in the best pitching conditions, a lot has to go right for a pitcher to complete a no-hitter. This remarkable play by José Abreu was the difference between Carlos Rodón throwing a no-hitter or joining a long list of players who just missed.

But it also stands to reason that certain conditions may contribute to a more favorable environment for no-hitters. First up: batting average.

The 2021 season, which has the lowest league-wide batting average since 1901, fits in neatly with 1908, ’67 and ’68 in terms of no-hitter frequency. The outlier here is 1909, a year where batters only hit .244, but one with zero no-hitters. Luck obviously plays a role, but pitching during a season where players are struggling to get hits generally corresponds to a higher incidence of no-hitters.

Another key indicator is the number of strikeouts per nine innings. Again, let’s look at the top five worst seasons for strikeouts (from the batter’s perspective), plus that season’s no-hitter rank:

This is muddled and has more to do with time than anything else. The top 15 seasons for strikeouts in MLB history are almost exactly the last 15 seasons, and they are almost perfectly in order: 2001 makes an appearance at No. 15, just edging out 2007. At this point, an annually increasing strikeout rate is pretty much the surest bet in baseball. But while the rising number of strikeouts is bad for any number of reasons, they are not particularly correlated with the rise in no-hitters.

I looked at a few other data points for this piece that don’t provide a lot of season-by-season insight, but do offer some interesting observations about the universe of no-hitters since 1901.

First, I looked at whether or not no-hitters tend to cluster in the early part of the season when the weather is colder, creating better conditions for pitchers. There is no discernable pattern there by year, but a large part of that is that there are so few seasons with more than one or two no-hitters that it’s just too small of a sample to evaluate. In the aggregate, however, it is worth noting that 33.6% of MLB’s regular-season no-hitters since 1901 have happened before May 15. Even in the seasons that have started earliest, teams have generally only played about 25% of their games by mid-May. So there are more no-hitters thrown in the early weeks of a season proportionally to the number of games.

I also wanted to take a look at whether there have been more near-no-hitters in 2021. To evaluate this, I added to a table Jay Jaffe created earlier this season when looking at the dazzling pitching matchup between Corbin Burnes and José Berríos, then divided the near-no-hit bids that lasted into the seventh into inning-by-inning buckets as to when they were ended. Finally, I combined the near-no-hitters with the four no-hitters on the books to get a total percentage of games played from this season:

You can clearly see a spike of almost no-hitters and no-hitters in this year’s data.

There is too much chance involved to predict that 2021 will shatter the record for no-hitters even with this remarkable head start. But with batting averages at an all-time low, no-hit bids are more common than ever, which means that 2021 could eventually go down as the year of the no-hitter.