Trey Yesavage showcases special splitter in spectacular start to his MLB career

Cruising through five levels of pro ball in a single year is almost unheard of, but Trey Yesavage managed to pull it off. On Monday night, he proved that even the final stop on that rapid journey might not be much of a challenge for him either.

Yesavage dominated in his debut start, striking out nine (setting a franchise record for most strikeouts in a debut), which showcased a fascinating approach built around a devastating splitter that looked virtually untouchable. The reason his splitter was so dominant against the Rays comes down to a couple of different things. The 6’4 righty has an unorthodox high three-quarters arm angle, which is extremely deceptive. His arm angle emphasizes a downhill motion, which is accentuated as his splitter dives down.

Trey Yesavage showcases special splitter in spectacular start to his MLB career

His splitter, which averages 84 mph, is also so effective because he tunnels it so well off his fastball, which averages 93-95 mph. Batters have virtually no time to decide between the splitter and the fastball because they are both dropping down from the high arm angle. His splitter, which has the chance to be one of the most effective pitches in the league, generated a 79% whiff rate on 14 swings.

Not only was the Boyertown, Pennsylvania native effective with the splitter, but he was also able to pound the strike zone with his fastball and slider as well. In terms of his fastball, he was able to throw it at a rate of 63%, while his splitter and slider landed in the zone at rates of 42% and 33%.

Yesavage's whiff rate on his fastball and slider ended up at 31% and 44%, which resulted in his overall whiff rate ending up at 52.8% (including the slider). The incredible whiff rate is the highest rate for any MLB pitcher in their debut, since tracking began in 2009.

The right-hander racked up nine strikeouts in his major league debut (six came from his splitter), following the same trend as what fans saw while he was in the minors. Across four minor league levels, Yesavage piled up strikeouts at an elite clip. In seven games at Low-A, his K/9 got up to 14.9. In High-A, he displayed a staggering 17.1 K/9.

The jump to Double-A brought some hiccups, but his strikeout ability still held up at 13.8 per nine. His Double-A concerns were highlighted in a Jays Journal interview with Sportsnet's Blake Murphy back in July. "The fact that Yesavage is struggling at Double-A is actually encouraging. Part of the reason they were aggressive with the promotion was because they wanted to see him deal with some adversity."

By the time he reached Triple-A, though, his K/9 ended up at 13.5 over six outings, which is still dominant. Long story short, Yesavage is a strikeout machine, which is a result of a nasty splitter from a deceptive arm angle, tunnelled by his fastball.