While on paper he might not seem like a breakout candidate, new Pittsburgh Pirates first baseman Ji-Man Choi could be on the verge of a great campaign with the bat because of the new shift rules.
Last Thursday, the Pittsburgh Pirates acquired Ji-Man Choi, hoping he could be a steady answer at first base. He’s silently been a good hitter for the Tampa Bay Rays, posting a wRC+ of at least 100 in each of his seasons with the Rays and a wRC+ over 115 in four of the past five seasons.
With a 120 wRC+ since 2018, Jose Abreu and Anthony Rizzo are the only free-agent first basemen who has a higher wRC+ throughout the last five seasons at 127 and 126, respectively. Overall, he’s been a better hitter than the likes of Josh Bell, Brandon Belt, Joey Votto, and Yuli Gurriel since 2018. While Choi may be entering his age-32 campaign, he may have a chance to be even better next season.
Choi is a left-handed power hitter. Like most lefty power bats, he pulls the ball quite often. His 40.7% pull rate was much higher than the average rate of 36.8%. While he wasn’t the biggest pull hitter in the sport, it was enough for opponents to shift on Choi. Opponents put their defense in a shift position 83.9% of the time when the first baseman stepped to the dish.
But it was effective in limiting Choi’s hitting potential. He managed just a .304 wOBA when the shift was on. 2021 shared a similar story. Opponents shifted on Choi more than three-quarters of the time and held him to a .328 wOBA. 2020 was the last time they didn’t shift against him more than they put the fielding formation in play, leading to a .272 wOBA in the 48.5% of the times they tried it.
However, when the shift isn’t on, Choi is an outstanding batter. This past season, he had a .415 wOBA when no shift was on. In 2021, his wOBA when no shift was put in place was .357, and .356 in 2020. Choi is consistently a below-average batter when the shift is on. But when the shift isn’t in play, he’s much better. A .360-.380 wOBA was the equivalent of a 135 to 150 wRC+ hitter in 2022.
The new shift rules could significantly improve Choi. Teams will be forced to leave two fielders on both sides of second base and have both feet on the infield dirt. While this won’t stop teams from playing their shortstop as close to second base as possible or moving their outfielders to a more opportune spot, it should tone down what we have seen with shifts recently.
Choi rips the cover off the ball. He was in the 88th percentile of hard-hit rate and 93rd percentile of exit velocity. Choi is already a good hitter, but he could be even better with the new shift rules. There are surely plenty of times he’s made good contact but hit the ball directly into the shift. Even if his wOBA only goes from .320-.330 to .340-.350, that’s still a major upgrade. Choi’s xwOBA is very close to .340 at .337. If he plays up to that, he’d be closer to a 120-125 wRC+ hitter rather than the 110-120 wRC+ hitter he has been for the past.