AP photo by Ted S. Warren / Detroit Tigers right-hander Spencer Turnbull became the fifth MLB pitcher to throw a no-hitter this season in a 5-0 road win against the Seattle Mariners late Tuesday night.

Sometimes, the simplest explanation is the valid one: The number of hits per game in Major League Baseball has plummeted, so no-hitters are on the rise.

Even so, this season has been a bit extreme.

When Detroit Tigers right-hander Spencer Turnbull finished off his gem late Tuesday night, striking out nine batters and walking two in a 5-0 road win against the Seattle Mariners, MLB's fifth no-hitter of 2021 was in the books, putting this season on pace to obliterate the modern record of seven no-hitters in a season.

The Mariners and the Cleveland Indians have been held hitless twice each, and of the 20 complete games pitched this season, a quarter of them have been no-hitters. Of the five pitchers who have thrown one, only two have ever been MLB All-Stars — John Means (Baltimore Orioles) in 2019 and Wade Miley (Cincinnati Reds) back in 2012.

And it's not yet June.

"I think it's still really hard," said Texas Rangers manager Chris Woodward, who was on the losing end when Joe Musgrove threw the first no-hitter in San Diego Padres history last month. "It's one of the hardest things to do in sports. Any time it's happening, any game I'm watching ... if a guy has a no-hitter through four, I'm always kind of intrigued."

It's hard to separate all these no-hitters from the context of what baseball looks like in 2021. Entering Wednesday, the average game included 7.83 hits per team. Only one season has ended with a lower figure, according to SportRadar. That was 1908, during the dead ball era. The other seasons when hits were the scarcest were 1968 — the famous "Year of the Pitcher" that led MLB to lower the mound — and two more dead ball seasons, 1909 and 1907.

Remarkably, there wasn't a single no-hitter in 1909 and only two in 1907, but there were six in 1908 and five in 1968.

The highest hits per game average since 1900 was in 1930, when it was 10.37 per team. Next up were 1925, 1921, 1936 and 1929. Not surprisingly, there were only two no-hitters combined in those five seasons.

"My instincts tell me the pitching is getting better," Cincinnati manager David Bell said. "The hitting is, too, but I do think that the way the arms are, the velocity the pitchers are throwing, the ability to spin the ball incredibly well, it's just a tough combination. And you get a guy on a good night when he's locked in, the scouting reports have gotten more exact, and it can make for a tough night."

One of the more unusual stretches for no-hitters came from 1988 to 1992. During that stretch, the hits per game ranged from 8.62 to 8.75 every season, but the number of no-hitters varied widely. There was one in 1988, followed by zero in 1989, seven each in 1990 and 1991 and back to just one in 1992.

From 2002 to 2006, there were only five no-hitters. In 2006, teams averaged 9.28 hits per game. That number has steadily decreased since then, and no-hitters have been more common, with seven each in 2012 and 2015.

In this era of hard-throwing relievers and fewer complete games, you might expect more combined no-hitters, but this year's have all been solo jobs.

"I think the surprising thing is that, you know, maybe in the age of pitchers not going 100 pitches, that they're actually being able to finish these games off. Because typically nowadays it's hard for a guy to get through six innings with less than 100 pitches," Woodward said. "That's probably more surprising to me. And there hasn't been a 160-pitch no-hitter yet, which is like gut-wrenching for a manager. I can't even imagine having to deal with that."

The number of strikeouts hasn't really been out of the ordinary in these no-hitters, and that might be part of the reason pitch counts weren't out of control. The average number of strikeouts in this year's no-hitters has been 9.2. Carlos Rodón of the Chicago White Sox had only seven in his no-hitter against Cleveland last month.

Perhaps the trend will subside a bit, but as long as hits are this hard to come by, a no-hitter will be a constant possibility.

The question is whether these feats will still draw as much attention.

"Every time you get close, that excitement, you can feel it in the dugout — I hope that never leaves," Kansas City Royals manager Mike Matheny said. "There's some excitement when you see, you know, this is tracking really well, we've had some really great plays, the innings are going by, maybe this could happen.

"I really hope fans don't start to think it's common."