Happ’s first half was atrocious: 5.02 ERA. His second-half overall wasn’t much better: 4.77 ERA. But he did pitch to a 1.65 ERA in September in 27.1 innings. His HR/FB rate dropped drastically from 30.8 percent in August to 7.1 percent in September.
If you look at his pitch usage by month, not much changed. However, one thing that did change was his fastball usage jumped from around 45 percent to 55 percent from August to September. The spin rate on his fastball stayed constant, but it appears as if the fastball is Happ’s strongest pitch. It has the highest spin of any of his pitches.