Last week “The Curious Case of Giant Strikes” detailed how the Yomiuri Giants were so good at getting called strikes in 0-0 and 1-0 counts from 2009 to 2019 that they could make the rest of NPB look like amateurs.

The Giants aren’t the only team whose strike rate on pitches taken by hitters was unusual over a period of time in some counts, but they were the most extreme. The data is confusing, but thanks to a reader’s suggestion that I look at individual players, umpires and home-road splits, I discovered some more interesting stuff.

My first study was focused on the period of Yomiuri’s extreme superiority in 0-0 counts between 2009 and 2019, but between looking at players and umpires, and trying different things with the program I used to model thousands of randomly generated seasons, three things eventually jumped out at me:

1. The real break occurred at the start of the 2018 season.
2. Yomiuri’s most unlikely advantage was not in 0-0 counts as originally expected, but in 1-0 counts, while its pre-2018 dominance in 2-1, and 1-1 counts was also more impressive than its results on first-pitch called strikes.
3. Although not a lot of pitchers worked many innings for both Yomiuri and other clubs during the 2009-2022 period in which I have data for, nine did. And as a group, these nine had an easier time getting called 1-0 strikes when they played for the Giants than for other teams.

Here’s looking at you, ump

In 2018, 11 teams, excluding the infamously penurious Hiroshima Carp, began sharing data from the Trackman pitch tracking systems they had installed in their main parks, so that Nippon Professional Baseball could use it for “umpire evaluation and improvement.”