Japan now has had four no-hitters, including one perfect game, and two near misses (Roki Sasaki’s perfect eight-inning game and Yudai Ono’s nine perfect innings when he allowed a hit in the 10^th) by the middle of June.

So what’s going on? Hotaka Yamakawa believes he knows, while the data suggests a combination of three things:

• A subtle change to the balls’ packaging this year.
• A gradual shift toward more bigger swings and uppercuts.
• A gradual shift toward faster and better fastballs,

The ball is not dead like it was before 1949 and again for much of the 1950s, when no-hitters were much more common, but it is slightly different this year. The big news this spring was that Mizuno, who used to individually wrap the balls in foil to preserve their moisture, upgraded their packaging further.

That shouldn’t be a huge difference, but it appears to have had some impact.

Nishinihon Sports quizzed Seibu Lions first baseman Yamakawa about it, and because the Lions have Trackman installed in their home park, “Your name here” Dome, he said there’s little mistaking those he hits on the screws that still end up in outfielders’ gloves.

“Pretty much when a ball comes off my bat with an exit velocity of 160 kph (99.8 mph), it’s gone. When I really drive one far, the exit velocities are around 180. Those balls this year, even when I get it on the sweet spot are home runs for sure, but they’re not carrying. They feel the same coming off the bat, but I watch the video and they’re not traveling.”

–Hotaka Yamakawa

The data supports that, although why fewer home runs would mean more no-hitters is the other side of the story. If it were just the ball not flying causing no-hitters, than with the dead balls in play for most of Japanese pro baseballs first 20 years, there should have eight to 10 a year.

The current ball is vastly more lively and uniform, but the game has changed dramatically. In 1949, the introduction of a smaller strike zone and the introduction of air drying for the baseballs created a home run surge that lasted until the ball issue was fixed in 1951.

1950’s absurd power numbers were also propelled by expansion, meaning more teams and more games, often in small substandard local grounds. But the surge whetted Japan’s appetite for the long ball, and though the parks improved, and the ball became less lively from 1951 to 1960, players began experimenting more and more with hitting home runs the way they did in MLB.

For the most part, Japan still teaches its young players to hit the ball on the ground between third and short to increase the chance of reaching base on an error, but the power game steadily gained ground.

Japan’s two big dead ball eras, 1936 to 1948 and 1951 to 1960 didn’t have more no-hitters because players were virtually never swinging for the fences. The game was 100 percent about making contact. More and more, it’s become about making HARD contact.

Which brings us to 2022. And while Japan is still a nation dominated by slap-hitters, MLB’s flyball revolution is casting a shadow. Using the percentages gleaned from Delta Graphs in the form of more fly balls, more swings and misses, and more hard-hit balls.

But batters aren’t the only ones informing their off-season practices and approaches with advanced metrics. Numerous pitchers have in the last few years gotten noticeably more backspin on their fastballs. According to Delta Graphs, the quality of fastballs in runs surrendered per 100 pitches has steadily ticked upward in the past three years.

This jibes with Yamakawa’s other assertion.

“The level of the average pitcher is high, make no mistake. They are faster than they were a few years ago. Now we take it for granted that starting pitchers can throw 150 kph (93 mph), and closers 160 (99 mph).”

— Hotaka Yamakawa

This year, swings and misses across Japanese baseball are at a high since 2014 when Delta Graphs began tracking them, while the percentage of hard-hit balls, which had steadily been increasing, has dropped.

The changes to batters’ approaches and pitchers’ fastballs would not have caused the upswing in no-hitters, but combine those with a deader baseball, and you get guys trying to hit more fly balls hard, but succeeding much less often because of the deader ball with less chance of making contact because of the pitchers.

So whose next? The Seibu Lions could be the first team to be no-hit three times in one year, if they catch a good pitcher on a good day on the road, where they are hitting .214 this year. But the Lotte Marines are most likely with their .207 road batting average.