He was pushed ahead of Joba even though Joba could finally pitch in 2010 without the infamous Joba Rules. The reasoning was because of the development of his changeup.
In 2009, coming out of the bullpen, Hughes was largely a three-pitch pitcher, throwing a fastball, a cutter, and a curveball. When his changeup showed improvement in spring training, they decided he had more value in the rotation than Joba did, and he took his place.
The funny thing is that once the season started, Hughes threw five changeups in his first start and didn’t throw another during the entire first month of the season. In May he never threw more than three in a game, and in June he didn’t throw more than two.
For the first three months of the season he threw just 20 changeups in total, according to PitchFX, and he pitched just fine. In 14 starts he had a 10-2 record with a 3.58 ERA.
Check out this chart I made up with information via PitchFX:
Essentially he had really hadn’t thrown his changeup much at all until the middle of August, except for one start on July 20th. In that start he allowed six runs in five innings.
Since August 31st he has thrown it a lot more, at least four times per start including 15 times last night alone. Has it really helped him out? In five appearances during that time he has gone 2-2 with a 5.40 ERA.
The changeup hasn’t really been that bad a pitch though. According to FanGraphs the pitch's value is -0.5, which isn’t great, but it’s close to league average. It’s not even his worst pitch, as his curveball has been valued at -5.6.
My point is that Hughes’ changeup doesn’t even seem to be necessary. He was successful early without throwing it much at all and has struggled mightily while throwing it often despite the fact that it hasn’t been valued extremely poorly. In reality, it’s possible that he really only throws the pitch when he’s in trouble.
That doesn’t mean he should give up on the pitch. It does mean that people shouldn’t get so excited when he is or isn’t throwing it. If he does, however, learn the pitch to the point where it becomes a weapon, it will obviously improve his game at that point. It would probably improve his curveball as well, as batters will not have the ability to wait on that particular pitch.
That’s going to take time though, so just because he threw a season-high 15 changeups last night doesn’t mean it’s automatically become a weapon. Hughes is only 24 years old, which is still incredibly young. In fact, last night he became just the second Yankees starter to ever win 17 games by that age. He’s still a work in progress though—just something to keep in mind.