After hitting just .166/.272/.212 from June through August with the Indians, Mark Reynolds now owns a .2879/.385/.489 slash with the Yankees in 52 plate appearances. I've already heard the word "rejuvenated" thrown around a few times, but it's much more likely that his improvements at the plate are a combination of small sample size and his new hitting coach.
“I’m getting my foot down earlier, trying to recognize better,” he said. “We looked at video and figured some things out, just basically trying to get my timing earlier and recognize the pitch and see it a little longer. So far it’s worked out. … It’s definitely got me on time more. I’m able to recognize more pitches and not swing at as many balls. I’ve been able to make better contact. Hopefully I can stay consistent with hit.”
After earning just 3 hits in his first 19 at bats with the Yankees, Kevin Long and Reynolds implemented a mechanical adjustment. Specifically, his stride step with the Indians began so early that he was hesitating at it's apex, leading to timing issues and poor momentum. Since August 25th, Reynolds has eliminated this pause, and has picked up 10 hits in his last 26 at bats.
In the GIF above, you'll see just how much longer Reynolds waits to make the step forward with his left foot. With Cleveland, Reynolds begins with his foot off the ground before the pitcher has lowered his own stride step, which leads to a pause in Reynolds' momentum forward. With the Yankees, Reynolds begins lifting his foot at the release of the pitch, which makes the pause unnecessary. Not only does this help his timing, but with removing that pause, energy is transferred much more fluidly. When looking at his front foot on contact with the pitch, you'll see that it absorbs much more energy with the Yankees than with the Indians, causing his foot to bounce towards the third base side.
This improved stride step should help Reynolds, but you can't expect him to continue his current rate of production. As I mentioned earlier, a combination of better momentum and timing, as well as luck, has given him confidence at the plate. If a simple timing change could affect him so much, there's reason to believe he could easily turn back into a pumpkin. For now, Yankee fans will be crossing their fingers for this hot streak to last for at least another month.