Clay Hensley pitches in relief for the Florida Marlins. After four season in San Diego, Clay discovered the virtue of the strikeout and recorded a career year. Through the end of 2008, Hensley struck out 5.7 batters per nine inning and walked 4.2 per nine, neither of those numbers very good. He only allowed 22 home runs in 323 2/3 innings, 13.6 per 200 innings, clearly his strength as a pitcher. All of that produced a useful but not great 4.09 ERA.

In 2010, his strikeout rate soared to 9.2 per nine innings, his walk rate fell to a decent 3.5 per 9 and his home run rate came in at 8 per 200 innings. That was good for a 2.16 ERA.

What happened? Clay did not pitch in the majors in 2009 after the Padres let him go. He pitched poorly for the Astros AAA team before the Marlins picked him up, and he started to reverse his K and BB numbers. Looking at his pitch selection, Hensley de-emphasized his fast ball in 2010 and threw a lot more curve balls and changeups. Those three pitches give the batter three different movements to think about:

Clay Hensley fastball movement 2010.

His fastball stays up in the strike zone, and he did a great job of keeping it in the strike zone in 2010, right at the upper edge.

Clay Hensley change-up movement 2010.

Like the fastball, the change-up comes in fairly straight, but dips instead of staying up. Hensley was also very good in 2010 at keeping this pitch on the inside corner for both right and left-handed batters.

Clay Hensley curve ball movement 2010.

The while the change up and fast ball change eye level, the curve ball changes everything. While the other two pitches move toward the catcher’s left side, the curve moves to the right and dives. According to Baseball Analytics (who supplied the graphs above), he gets 54% of his strike outs on the curve. He also throws the three pitches with very different velocities, 90 MPH on his fastball, 82 on the change-up and 71 on the curve. His 2010 season stands as a great example of how pitching is more than just throwing hard, it’s upsetting timing.

All of this led to Hensley taking over the closer role late in the season for the Marlins. We’ll see if 2010 was a just a fluke, or if batters continued to be baffled by the off-speed pitches.

As a side note, Hensley gave up Barry Bonds 755th home run and Clay was also suspended for steroid use in the minor leagues. I suspect he wants to continue to pitch well so those are not the most noteworthy items about him.