Was Astros' Lance McCullers Jr. tipping his pitches through different leg kick?

There are two notable differences in the videos.

1. McCullers had more back leg knee bend in one video and less in the other, resulting in a different type of leg kick.
2. Another big difference, and one that would be visible to a hitter, is the height of McCullers’ glove when he kicks his front leg. When his glove raised very high to the top of his head, he was throwing a breaking ball. When his glove height was lower towards his chin, he was throwing a harder sinker.

Although those differences were visible in the video clip shared by Leg Kick Nation, it’s hard to tell later in the game how McCullers was tipping. He changed his windup so that he was holding his hands higher on his leg kicks. He also seemed to have a similar leg bend later in the game too.

Here are some of the home runs the Phillies hit for comparison.

Bryce Harper (curve):

Alec Bohm (sinker):

Brandon Marsh (slider):

Kyle Schwarber (changeup):

Rhys Hoskins (slider):

It’s hard to identify any noticeable difference in McCullers’ motion and glove height in those videos. But based on how well they hit McCullers, and the tips they passed along, the Phillies seemed to know something.

It could be that McCullers fixed his tipping early in the game, but then stopped throwing his sinker later in the game, which allowed Phillies hitters to narrow down their choices and sit on the slow stuff.