Having examined what happens when individual batters come off the bench to hit in NPB, and knowing that pinch-hitters, as a whole, are less productive in that role than they are when taking their regular turn in the batting order.

While the pinch-hitting penalty described by Tom Tango, Mitchel G. Lichtman and Andrew E. Dolphin in “The Book” does not appear to be nearly as extreme in NPB, their advice holds. Because they calculated that pinch-hitters wOBA is .034 less than when they bat in other contexts, they recommend managers only hit for position players using guys off the bench who are significantly better hitters.

Even if the pinch-hitting penalty is only .006 points of OPS2, it would behoove managers to at least use pinch-hitters who are somewhat better, because some managers don’t even do that.

In terms of the OPS2 managers have sacrificed and production gained during the period studied, here are the NPB managers who gotten the most mileage out of pinch-hitting for position players:

The next table gives the 20 managers who’ve replaced one position player with another at least 200 times between 2002 and 2018 and who got the least mileage for their changes.

In these lists, a few managers are given twice — for results with individual teams and for all the teams they managed during this period combined.

Least productive managers when pinch-hitting for position players

So the most successful employer of pinch-hitters in recent years was a playing-manager, Motonobu Tanishige, who often delegated bench decisions to his head coach, Shigekazu Mori, while No. 2 was Hall of Fame manager Akira Ogi, who was manager for only one year during the study, 2005, before his untimely death.

At the bottom of the table is the late Koji Yamamoto, who managed the Lotte Marines before Bobby Valentine took over the reins in 2004. Another Hall of Fame manager, Senichi Hoshino, finishes second worst with the Rakuten Eagles, and third worst for his time with both the Hanshin Tigers and Eagles combined.

And then there are the managers who’ve chosen, on average to replace position players with pinch-hitters of lesser value. The good news for Marines fans is that while Iguchi made some ostensibly dreadful choices last season, they did not hurt his club, since the pinch-hitters exceeded anyone’s expectations — except perhaps the skippers’.

Silly pinch-hitting choices