The Cleveland Indians may have gotten an early Black Friday deal in trading essentially nothing to the Tampa Bay Rays in exchange for Kirby Yates on Wednesday. Yates, a 28-year-old right-handed relief pitcher, had a season-long struggle with home runs that inflated his ERA to 7.97 in 2015. In only 20.1 innings, He gave up 10 home runs and 18 total earned runs while striking 21 batters and walking seven. Then, just days after being designated for assignment by the Rays, Yates was traded to the Indians for cash considerations. But why?
From the Indians perspective, the move is a low-risk, high-reward possibility. The biggest risk for the Indians, if he turns out to really be a pitcher who cannot help but allow a home run in every single outing, is that he will take up a roster spot. But on the other end, if having a 30% home run/foul ball ratio is just a fluke (hint: it probably is), they could be getting an excellent relief option out of Yates. No team, especially one managed by Terry Francona, can have too many relief options.
Before making his Major League debut in 2014, Yates was a strikeout machine in his five seasons as part of the Rays farm system. Despite an average 93 mph fastball, Yates hides the ball well and he worked a positive slider to strike out roughly one out of every three batters he faced at any given levels in the minors. When he did make it up to the Majors, Yates continued striking batters out in 2014 with a 26.9% strikeout rate and in 2015 with a 22.8% strikeout rate.
It is difficult to pinpoint exactly what caused Yates’ 2015 season to go awry, but it all went from bad to worse when he began to use his slider less and rely on his curveball more. Yates looked okay in his first four appearances of 2015 (4.1 IP, 7 H, 2 ER, 5 SO, 0 BB), but a strained pectoral muscle lead to an extended disabled list trip, and he would not appear back on the Rays roster until June 26 when everything began to unravel.
Yates went through a span of six relief appearances--spread out between June 29 and September 1--where he allowed seven home runs, 12 earned runs, and had an ERA 14.73. Obviously noting something was wrong, Yates began to decrease use of his slider until it was not even thrown at all several games in a row, and instead opted to use a curveball that he rarely used prior. The results still were not spectacular, but at least he kept his home runs down. Yates finished 2015 allowing four earned runs and two homers over his final eight appearances.
You can see pretty clearly in the table below from Brooks Baseball, that as Yates became less effective into August he tried adjusting away from his slider. This is not a pitcher who had a total meltdown and forgot how to pitch. His primary offspeed pitch was not working and he could not adjust well.
Yates’ 2015 downfall is closely linked to his slider becoming ineffective, whether that is through injury or his own inability to locate it for whatever reason. If Indians pitching coach Mickey Callaway can work with him and help him get back to the same near-dominant slider that he carried throughout his minor league career and parts of 2014, the Indians come away with a steal from the Rays. Otherwise, they have a guy they will designate for assignment after he does not make the team out of Spring Training. It's clear the Indians see something that they can fix with his approach, we just have to hope they are right.