Raise your hand if you expected Phil Humber to have the lowest ERA on the starting staff as of today. Put your hand down, Nobody. We've had it up to here with your told-ya-sos. Outside of Nobody, Humber was expected to be replacement level. Pretty reasonable inference, seeing as the guy is older than Gavin Floyd and had all of 2 career MLB starts coming into 2011.
And after seeing his first couple starts, I was still unimpressed. Underwhelming fastball, meh change. Solid curve, but there aren't many starters who survive off their curve alone. I can't think of any offhand. But at this point Humber's performance merits investigation. Because not only does he have the staff's best ERA, but the best FIP too. The underlying foundation supports the results. At least to a degree, anyway; we're still in small sample size territory.
So how much is smoke and mirrors? A decent amount, but Don Cooper's doing his best to make a paper tiger into a real one. As 3E8 pointed out, Humber has added a slider to his repertoire:
blatantly stolen from 3E8's comment
If you click through to the comment (which should have been a fanpost, pal) you'll see that there was evidence of a slider-in-progress in the earlier starts and it's since become a full-fledged part of the arsenal. And it's getting great results so far. Against the Orioles and Yankees, I count 12 whiffs on 31 sliders and 4 whiffs on 20 sliders respectively, for a total of 16/51. It dominated the Orioles and held up against the Yankees. In those two starts, I'd count it as a legitimate out pitch. The other options in his arsenal are not, so if it holds up the slider stands as a significant development.
Without it, he lacks the stuff to survive in the MLB as a regular starter. His fastball is a classic four-seamer with considerably more rise than run. So he can't use it to get ground balls and since it sits 88-92, he's vulnerable to both lefties and righties when he doesn't spot it. As far as that goes, he's demonstrated a pretty clear weakness. He can't hit the catcher's mitt it to his glove-side. So against lefties inside and righties away, he's shown a tough time hitting the spot AJ shows. To the throwing arm side, he's able to keep it down, but doesn't seem to be able to move it up under the hands of RHB where he might get a grounder.
This would be less of an issue if his change were any good, but it doesn't seem to be. He has a tough time spotting it and it doesn't appear to have much fade. It tends to end up on the fat part of the bat rather than disappearing under it. Brian Roberts rocked one for a double in the first inning and Markakis followed it up with a warning track shot off the very same pitch: right down the middle, no movement. Very well could have been back-to-back bombs. Unsurprisingly, he's all but abandoned it as the slider has developed.
His third non-slider pitch, the curve, is the best of the trio, but tough to judge. Gavin's buckles knees on a regular basis, even (or particularly) late in the count, whereas Humber's really doesn't. But it's still better than the show-me early-count curves we've seen from a number of pitchers so far. If I had to call it anything, it's a pitch-to-contact type, like a sinker. Batters haven't seemed to hit it very hard, so he can throw it whenever in the count. But it's not a wipe-out offering like Gavin's.
Between those three pitches, you can see why he'd be in trouble. Throwing curves for strikes on a regular basis is difficult, which means you can't throw too many. But substituting it for a fastball or change isn't a great trade-off either. He really needed another legitimate, reliable plus pitch and with Coop's tutoring, he seems to have found one.
That said, I think teams have yet to adapt to the existence of this new pitch. There's a fairly obvious approach to avoiding the slider as long as Humber struggles throwing his fastball to his glove-side: don't swing at anything to that side. If he shows he can consistently hit that spot against righties, he'll be very tough against them. Until then, he'll keep making mistakes up and out over the plate. With his fastball, it's not really something he'll be able to overcome.
LHB will probably struggle a bit in laying off what looks to be a fastball in the wheelhouse, but if they can, he really doesn't have much else to get you out with. So far the change has been a homer waiting to happen. His curve lacks the kind of downward bite to be very effective against them. To sound like Hawk for a second, I'd move around in the box. Rather than using an opposite-field swing, crowd the plate to guard against rolling over the fastball away. Without a strikeout pitch, it's a matter of time before he leaves a fastball or curve up.
If Humber can't command his fastball in order to set up his best pitch, he's still going to be a below average starter as hitters adapt to the new offering. Which is not to say there's no counter. Between improved command and a cutter, he'd have an arsenal enough to set up his out pitch and attack both lefties and righties. At that point, I think he could actually transition from a poor-man's Gavin Floyd to a starter of approximately Gavin's caliber.
Even if he never gets any better, it's one more feather in Don Cooper's cap. He really is the best pitching coach in the majors. Or if he isn't, he's severely underpaid. There's no way he's not worth at least 1 WAR per season. That goes for about 5 million in free agency.
What I'm saying is talk to me Coop. I'll getcha paid, yo.