There is a lot of video of Joc making small adjustments (below), but it really didn't hit me until the end of 2017. Two games left in the season. He had already been sent out from the big league team. I was up in the big leagues and I went out to triple A with him. I bounced a lot of things off of him on the flight, we landed, and went to work. Still, I could tell by how the hip line was working that he was still underneath the ball. He got called back up. Wasn't playing much, and we were still working on getting his momentum and hip line working in the right direction. With two days left in the season, I approached Joc and said I have something for you. You need to stay open, you need to have you foot stay pointing down. And you need to get it down ASAP, and that's what he did

He was getting his front knee turned in toward home plate, which took his hips and slid them forward and underneath him.  

Once the hip was pushed forward, he had no choice but to lay his barrel back behind him, which would make him underneath most pitches

Swings compared from the 2nd to last day and the last day