Jerome Williams of the Los Angeles Angels of Anaheim made a triumphant return to the majors on Sunday. He did not walk a batter, striking out six during seven innings of work, allowing his only run on a solo homer. After the game, Torii Hunter commented on Jerome's improvement:
"He just re-created himself," Hunter said. "He's throwing two-seamers, cutters. He's not throwing the straight fastball anymore. He's keeping the ball down and it seemed like he just learned how to pitch."
Hunter makes very good points. Not only is Williams keeping the ball down, he developed a septum chart, working the edges and avoiding the middle of the plate:
It's just one start and one relief appearance, but that kind of separation between inside and outside shows up in the best pitchers. Now look at the spin of his pitches:
The curve ball (blue smudge) and slider (yellow circle in the middle) stand out. The green/yellow/orange circle, however, represents his fastball and change up. It's that orange blob that is intriguing. The relationship between a normal two-seam fastball and a change up is that the fastball "breaks up and in" more than the changeup. This fastball does break in more, but it actually breaks down more as well. In other words, Williams appears to throw this pitch with less top spin than expected. A two-seam fastball works off the four-seamer. Pitchers want to throw them the same way, and let the position of the seams cause the rise and dip. Without a four-seamer, Jerome appears to be concentrating on making the pitch dip.
Hunter also mentioned a cutter, which doesn't show up on the above heat map. It's there, but Williams did not throw it much:
You can see the tiny smug on the Y axis just above the X axis. That's the cutter, but he hasn't thrown it enough yet for PITCHf/x to classify it as such.
Williams made a good start against a last place team. Now he needs to repeat these pitches, and see if he can beat Texas next weekend.