A week or so ago, author Robb Fitts posed a two-part question to our podcast about whether there was data to support my assertion that the ball being used in NPB in recent weeks was actually livelier than the ball in play from the start of the season, and if so, does that account for the Carp’s late-season lack of buoyancy.
The ball has been changed
In short, the answer to the first question is “most likely.” The ball in play now is deader than the ball in play at this time of year the past three seasons, but is nothing like the disaster of a ball that NPB began the season with.
Prior to July 1 this season, 3.7 percent of balls that went out of the infield were home runs. From 2021 to 2023, the percentage was 5.9 percent, 36.6 percent less often. I didn’t include 2020 because the season didn’t start until June 19 because of the pandemic.
From Aug. 15 to Sept. 13, the percentage of balls into the outfield that reached the seats this year was 5 percent. In the previous three years it was 6 percent, a decrease of just 16.8 percent.
Both Mizuno and NPB, have insisted that no changes have been made to the ball, but the steady annual decrease in home runs makes that answer sound implausible. For one reason or another, perhaps to shorten the time it takes to play games, NPB has worked to make each season’s balls less lively than those of the previous year.
It seems the balls intended for 2024 were substandard, and had to be replaced. My guess would be that balls originally intended for 2025 were rushed into service as soon as enough were ready.
Of course, the drop in home runs is not entirely due to the ball, but also partly to players’ tactical responses to the ball, the way pitchers attack hitters and the balls hitters chose to put big swings on.
On the team level, sacrifice bunts as a percentage of runners on first base have increased by 20 percent in 2021 and 2022, and another 10 percent further this year, suggesting that teams are bunting more in response to the lack of offense. The shift might have been more drastic if it weren’t for new Hawks manager Hiroki Kokubo restoring normality after taking over from small-ball fanatic Hiroshi Fujimoto.
The Carp and the dead ball
This was an astute bit of reasoning on the part of Mr. Fitts that should have been obvious to me long before. The Carp hit the ball on the ground more than any team in NPB, and make hard contact less often than any other team in Japan.
Through June 1, the Carp hitters were hitting home runs on 3.5 percent of the balls they got out of the infield, their opponents on 3.1 percent, so it’s fair to say that the Carp were really good at limiting home runs when the balls were dead.
Since Aug. 15, the Carp have been as bad at hitting home runs as they were before, their ground-ball, contact-oriented approach has made virtually no difference with a livelier ball. On the other side of the coin, the Carp pitching, once so good at preventing home runs, have struggled and are giving up home runs about 77 percent more often.
Yusuke Okada, the founder of Delta Graphs, wrote how the lack of home runs this year made pitching and defense even more important, and the teams that have risen to the top years are by and large the better defensive teams. According to Delta Graphs, the Carp have not been the best team in any single defensive metric, but they have been better than average at everything, while the pitchers have given up less hard contact.
