The Yankees are struggling right now for two reasons. The main reason they're struggling is because this isn't the same team that has been on the field the last two seasons. Injuries and age have decimated the Yankee lineup. The players picked up to fill in the gaps (Vernon Wells, Travis Hafner) simply aren't as good as the players who are missing. But the second reason the Yankees are struggling is because the star players who aren't hurt are not playing as well as they have in the past. Ichiro Suzuki has an 86 OPS+. Robinson Cano has a .492 SLG. And CC Sabathia has a 4.15 ERA. The first two examples of struggling stars aren't huge surprises. That's who Ichiro was when the Yankees first acquired him. He stepped into the way-back machine for the end of last year. Cano, meanwhile, is prone to struggles. He may yet get hot and finish the season around his career averages. But CC is a surprise. The summer is upon us. The days are long and hot. Isn't this the time when the big guy is supposed to be already going, knocking off a string of dominant starts? Instead, Sabathia has been average. What's going on?
Sabathia appears to be suffering from two problems. The first is his fastball. CC employs two lethal out pitches: His slider and his changeup. Those are working fine. Per 100 pitches thrown they've been worth 1.43 and 1.27 runs respectively. To get to those pitches CC likes to paint the corners with his fastball. He doesn't need the fastball to be an out pitch, but he needs it to be reliable enough to get him into a two strike count. This year his fastball has been a vulnerability. Per 100 pitches it has been worth -0.33 runs, versus having been an average pitch for his career. His fastball velocity is down at 90.7 mph versus 93.4 for his career. Unsurprisingly, he's giving up a record 1.31 homers per game, nearly twice his 0.82 career average. A bad fastball is prime meat for a big league hitter.
The interesting thing is that as bad as CC's fastball has been this year, it was worse last season. In 2012 CC's fastball was worth -0.73 runs per 100 pitches. 2012 was a good season for CC. His slash line was 3.38/3.33/3.20. His fastball is better this year, but his line is 4.15/3.93/3.51. That highlights CC's other problem this season. He's getting unlucky.
Apart from the extra homers that he's giving up, which are bad, CC's numbers look close to what he's put up for his career. He's striking out 7.46 batters per nine innings, right on his career average of 7.76. He's walking only 1.77 batters per nine, which is well below his 2.66 career average. His BABIP is .292, literally his career average (.291). Suddenly CC's 3.51 xFIP on the season makes a lot of sense (credit rasco). Remove those extra homers and he's the same pitcher he's always been.
Luck is a tricky thing to analyze. Is CC putting up standard numbers with worse results because he's truly getting unlucky, or is it because something else has changed that is harder to identify in the numbers? It's impossible to say. What is clear is that CC's performance is another example of why the Yankees are struggling this season. Not only is the team full of replacement players, but the mainstays are having sub-par seasons as well.