look at this clip
It looks to me like Zumaya’s lead foot lands off to the thrid base side, relatively to where he starts on the rubbder.
Look at the location of his back foot and his front foot at the point when he lands it. The guy is throwing across his body. This is frowned upon. And yet he’s gunning it in at 103 mph … go figure.
On a side not, look at that third pitch he throws. Look at the location and speed on that. It will make you sit back in your seat. Very exciting stuff.