Houston Astros pitcher Tatsuya Imai is having an awful rookie season in Major League Baseball. Over 41 innings, he has allowed 35 hits and 24 walks, which have contributed to him giving up 28 runs and accumulating an earned run average of 6.15.

Imai’s poor performance stems from his pitching strategy. Over his first ten starts, he has struggled against left-handed hitters, who have a .256 average and 4 home runs. Most of this damage has come from his four-seam fastball.

Left-handers are hitting .423 against the four seamer with 1 home run. When Tatsuya Imai throws a fastball to a left-handed batter, the pitch tends to land over the middle or on the outer half of the plate. 

Over his first 10 starts, 116 of his fastballs have been in these two locations, accounting for 61.7% of the time. The fastball ends up in these locations because it has significant horizontal movement.

Tatsuya Imai has a fastball with 12.8 inches of arm-side movement, the 29th-most among all pitchers. The arm-side movement means the ball moves to the right, as he is a right-handed pitcher.

Left-handed batters are hitting .533 when fastballs land over the middle or outer half of the plate. Imai performs much better when he throws pitches on the inner half of the plate to left-handers, as they only have a .200 batting average in this location. 

Imai should throw more curveballs to lefties, as it’s his only pitch with glove-side movement which means it is moving left toward the batter. The curveball has 8.1 inches of glove-side movement.

In 2026, Imai has thrown just six curveballs to left-handed hitters across three at-bats. His most recent curveball was on April 8, 2026, against the Athletics.

Right-handed specialist

Given Imai’s pitch selection, focusing more on the curveball could help him retire left-handed hitters. Otherwise, he needs to be a specific type of reliever, a right-handed specialist for the remainder of 2026, as it is hard to learn a new pitch mid-season.

Imai has been significantly more successful against right-handed batters. Right-handers have an average of .194 with two home runs.

The increased success against right-handers is related to his ability to locate pitches on the inner half of the plate. He has thrown a total of 294 pitches to right-handers, 152 of those have been on the inner half of the plate, 51.7% of the time.