Orioles left-hander Brian Matusz has endured a trying 2011 season. The 24-year-old missed the first two months of the year with an intercostal strain. In five starts this June, Matusz has been thrashed for a 6.85 ERA in 22.1 innings. He has a middling 16-to-10 strikeout-to-walk ratio, and has surrendered seven home runs while posting the lowest ground ball rate (about 25 percent) among starting pitchers.
Since returning from his injury, Matusz's fastball has lacked zip. He threw his fastball at an average of 90.1 MPH over the 2009 and 2010 seasons, but he's averaging just 87.2 MPH with the pitch in 2011. His changeup, however, has basically stayed at the same velocity: 82 MPH from 2009-2010, and 82.3 MPH in 2011.
The speed differential between Matusz's fastball and changeup has dipped from a little over eight MPH to less than five MPH. And while his changeup previously had around two fewer inches of vertical break than his fastball, the two pitches are nearly indistinguishable in 2011.
Take a look at the pitch break and velocity of Matusz's fastball and changeup from 2009-2010:
There's a clear difference in speed between the two pitches, and the changeup dips a bit compared to the fastball. Now, look at the pitch break and velocity on Matusz's fastball and changeup this year:
If you can't tell the difference between the fastball and the changeup, that's exactly the point. There's little difference in either velocity or movement between the two pitches. It's hard to say that Matusz's changeup is actually, well, changing up from anything. Both pitches just look like slow fastballs.
Compared to 2009-2010, Matusz is getting far fewer misses and strikes with his fastball and changeup:
2009-2010: 14.5 Miss%, 64.8 Strike%
2011: 6.5 Miss%, 58.3 Strike%
League Average For LHP: 15.8 Miss%, 63.8 Strike%
2009-2010: 32.1 Miss%, 63.9 Strike%
2011: 23.4 Miss%, 61.7 Strike%
League Average for LHP: 28.7 Miss%, 62.4 Strike%
Oppponents have teed off on Matuz's fastball to the tune of a .314/.390/.600 line in 2011. Basically, every hitter turns into David Ortiz aganst Matusz' heat. For comparison, opponents batted .278/.361/.439 against Matusz's fastball from 2009-2010, and the league average for lefty fastballs is .270/.352/.421.
His changeup has fared even worse: a .359/.432/.615 opponent line in 2011. That's Ted Williams-esque. Matusz's changeup had a .286/.322/.422 line from 2009-2010, and the league average is .254/.324/.389.
It's also not a stretch to think that Matusz's fastball/changeup problems have harmed the effectiveness of his mid-70s curveball. Hitters only have to tell the difference between Matusz's not-so-fast fastball, slightly slower change and a curveball that obviously breaks much differently:
You'd have to think that it would be easier for hitters to identify what Matusz is throwing (or guess right more often) with what looks like two different pitches instead of three (he has rarely thrown a slider this year). Batters have a .300/.300/.500 line this year against the curve. From 2009-2010, they hit .195/.205/.366. The league average is .217/.255/.315.
For Matusz's fastball/changeup combo to work, there needs to be some actual differentation between the two pitches. Otherwise, the lefty is just throwing a bunch of 80-something MPH batting practice pitches.