Jorge de la Rosa: Reverse Splitter

You know it’s late in the season when a Fantasy Baseball blogger can’t think of anything more constructive to do than recommend a Rockies pitcher. But stay with us for a moment, because we think we’re on to something.

More precisely, we think Mike Petriello, late of Fangraphs and dweller in stat Valhalla, was on to something six months ago. In early March of this year, a Denver Post article about Rockies’ starting pitcher Jorge de la Rosa caught his eye. As you no doubt know, Coors Field is a real tough place to pitch. And so it was for De La Rosa from 2008, when he joined the Rockies, through 2012. His home/road splits were big, though not really different from anyone else’s. Then, in 2013 and 2014, a very strange thing happened: De La Rosa was lights-out in Coors, but sub-mediocre everywhere else. Merge his 2013-2014 Coors stats and you have a Cy Young candidate: 29 starts, 20 Wins, 3 Losses, 2.92 ERA, 1.24 WHIP. Merge his two-year stats on the road and you’re in Jeremy Guthrieland: 33 starts, 10 Wins, 14 Losses, 4.66 ERA, 1.38 WHIP.

When something this surprising happens, you go looking for explanations. The Denver Post article wasn’t altogether illuminating on this score. Its headline was: “Rockies’ De La Rosa will use great changeup to improve on the road.” To the uninitiated, it might have sounded like de la Rosa had a new pitch, but in fact he’s always had a great changeup—or splitter, if you prefer, since he throws it with a splitter-style grip. So this already-great changeup/splitter hadn’t helped on the road for the last two years. What was new? De La Rosa was kind of vague: “I have to be more consistent on the road….I know that it’s something I have to work on.” But what’s he going to say? It’s the start of spring training, and even if de la Rosa has a particular adjustment in mind, it’s probably so subtle and ineffable that it’s hard to explain. The closest he can come is to say that he feels like he’s got better control of the changeup at Coors, where he feels “more comfortable.” In Coors, de la Rosa thinks he can throw it on any count, whereas on the road, apparently, he can’t. And why is this? Because, he says, “on the road the breaking ball breaks too much.”

As far as we know, no one’s ever said this about Coors before. Petriello tries rigorously and heroically to get to the bottom of this, but concedes that he really can’t. He can’t find anything to suggest that De La Rosa is getting fewer strikes on the road with the changeup/splitter, or even that he’s throwing it a whole lot less on the road. Petriello warns that FIP numbers suggest that the reverse-split have been an illusion, at least in 2014. Otherwise, the best he can do is to propose that “[t]he simplest answer is that De La Rosa has found the right mix specifically for his unique set of pitches that works in Coors Field.”

So has de la Rosa found the philosopher’s stone in 2015? In some measure, things have turned out exactly as De La Rosa hoped: he’s throwing way more changeups/splitters and, no doubt as a result, producing way more ground balls than is his custom. And, surely for this reason, he’s been excellent on the road: 12 starts, 3.22 ERA, 1.20 WHIP. More particularly, in four starts on the road against his NL West rivals, he’s got 2 Wins, 2 Losses, 2 Quality Starts, a 2.74 ERA, with 25 baserunners and 23 strikeouts in 23 innings. Fantastic, right? Except he’s been terrible at Coors: 5.40 ERA, 1.56 WHIP.

We can’t come close to explaining this, though we’d love to see de la Rosa, Petriello, or both of them take a crack at it. Maybe it’s just that baseball is so hellishly hard and microscopic adjustments so difficult to achieve, reproduce, and then microscopically readjust that whatever it is that now enables De La Rosa to deploy his changeup on the road more frequently prevents him from using it effectively at Coors.

Happily for de la Rosa and perhaps for us, the Rockies’ schedule from here on is propitious. It looks to us as if de la Rosa will get five more starts this season: four on the road, with one against each of his NL West rivals, and one at home against Pittsburgh. Let’s say, or anyway let’s hope, that he duplicates the stats from the four NL-West road starts he’s already made. The start at home is worrisome. But de la Rosa has faced the Pirates twice in Pittsburgh in 2014-2015, and has been superb: 12 innings, 12 baserunners, 1 earned run, 9 strikeouts. The Bucs haven’t visited Coors this season, but last season they didn’t exactly set it alight: 7 runs in 3 games.

So if we’re right about this, you’ll get a couple of wins, a couple of quality starts, close to a strikeout an inning, and an ERA and WHIP that will help. And de la Rosa is probably out there for the taking: he’s owned in only 9% of ESPN leagues and 8% of Yahoo leagues. All of which makes him a Birchwood Brothers Pick Hit, especially against the punchless Padres in San Diego tomorrow night.