Jorge De La Rosa, The King Of Coors Field

Last July, Rockies owner Dick Monfort earned some well-deserved ridicule by indicating that his team wouldn’t consider trading 33-year-old free-agent-to-be Jorge De La Rosa, despite the fact that Colorado was well on its way to a 96-loss season and De La Rosa is, all things considered, pretty mediocre and not even that durable. The owner’s money quote: de la Rosa “has won our last three,” without noting that the three wins had required 21 Colorado games to attain. According to a Peter Gammons report, Monfort killed a potential deal that would have sent De La Rosa to Baltimore for Eduardo Rodriguez, who was instead swapped to Boston for Andrew Miller and has impressed so much since that he ranked No. 23 overall on Kiley McDaniel’s recent Top 200 Prospects list.

While Rockies fans cringe at that thought and pray that Gammons’ information was incorrect, the Rockies instead gave De La Rosa two more years and $25 million in September. Considering that the team’s major additions this winter were minor pieces like Daniel Descalso, Kyle Kendrick, John Axford, Nick Hundley, and David Hale, it’s looking like another season of praying that this is the year that Troy Tulowitzki and Carlos Gonzalez stay healthy at the same time, while hoping that young arms Jon Gray and Eddie Butler can contribute.

While it’s difficult to see a scenario where the Rockies break through this year, it’s perhaps even more difficult to see De La Rosa still being around to contribute to the next good Colorado team. But while Monfort’s direction and baseball sense may have been misguided, he’s not wrong about one thing: “he pitches great here,” and in a sport where finding any pitcher who can be anything other than awful in Coors Field has proven terribly difficult, maybe that’s not such a meaningless thing to have.

While De La Rosa has been with the Rockies since 2008, Tommy John surgery and a finger injury limited him to only 191.1 combined innings across three seasons (2010-12), so for the moment, we’re focusing only on his last two mostly healthy seasons. I draw your attention to… well, everything, but mostly the ERA / FIP / wOBA columns. In 2013, he was enormously better in Coors Field. In 2014, he was enormously better in Coors field.

	IP	ERA	FIP	wOBA	BB%	K%	K%-BB%	GB%	HR/FB%
2013 Home	81.2	2.76	3.07	.309	6.7	16.3	9.6	47.7	4.5
2013 Away	86.0	4.19	4.42	.327	10.5	15.1	4.6	46.9	10.4
2014 Home	90.2	3.08	4.00	.295	8.0	17.7	9.7	53.1	12.0
2014 Away	93.2	5.09	4.67	.332	9.3	18.4	9.1	50.2	13.6

Needless to say, given all that we know about Coors Field, this just doesn’t happen. How does this happen? Maybe you’d like to see a larger sample size than this — though it should be noted that in 2010, the last time he’d had 100 innings pitched in a season, he had similar splits (3.34 / 5.52 home / away FIP). Probably, yes. It feels weird to call this a “skill.” That said, De La Rosa has found a way not only to survive but to thrive in Coors, and just about no one else has been able to do the same. It’s not quite that “managing not to get killed in Coors” should be an award category of its own at the end of the season, but it’s not not that, either.

But it’s not even really the fact that De La Rosa has been successful at home that’s interesting, because we’ve seen that before. For example, the two best pitching seasons in Rockies history — Ubaldo Jimenez‘ 2009 and 2010 — featured Jimenez being dominant on the road and good-enough at home. It’s how you’d expect a Rockies starter to succeed. In this case, it’s that De La Rosa has been good at home and so, so much worse on the road, and that’s unique. How? Why? And, for good measure, let’s say who, what, when and where as well.

If you listen to De La Rosa, he both knows the cause and has a plan to combat this. Last year, he told MLB.com why he thought he was having trouble on the road:

“I like it here because I can command my pitches here,” he said. “When I go on the road the breaking ball breaks too much. I have trouble keeping it in the strike zone. It’s not as comfortable as pitching in Coors Field.”

“Comfortable!” In Coors Field! From a pitcher! In a recent Denver Post article helpfully titled “Rockies’ Jorge De La Rosa will use great changeup to improve on road,” he indicated how he planned to fix that:

“I guess I just feel more comfortable at home,” De La Rosa said, shrugging his shoulders. “I just feel like I have control there, especially with my changeup. I feel like I can throw it in any count.”

Is De La Rosa’s change important enough to him that having an (apparently) better version of it at home makes that much of a difference? Is he throwing it less often on the road? Is his breaking ball really so uncontrollable that rather than having his movement flattened out into something ineffective by Coors, the altitude affect makes what’s a mess of a pitch into something resembling effectiveness? I’d love to run comparables here. There just really aren’t any.

We have Baseball Savant. We can test this. Sort of. See, De La Rosa pretty clearly says he throws a changeup. Just look at the quote above! PITCHf/x, which fuels Baseball Savant, says he doesn’t. Brooks Baseball, which uses PITCHf/x as a starting point and then hand-edits as needed, also says he doesn’t. Rather than a change, his pitch is described as a splitter, because of the grip.

Regardless what you call it, it comes in around eight to nine miles slower than his fastball, and it looks like this…

…but since it’s “splitter” in the data, that’s what we’ll call it from here on out.

On the road, over the last two years — and these numbers are all going to be from 2013-14, so I’m not going to say it every time — De La Rosa has thrown the split-change 23% of the time. At home, it’s 25%. That’s more, though not considerably so, but he’s had more swinging-strike success (15.8%) in Denver than he has everywhere else (13.8%). It’s pretty clear that it’s his best pitch, and especially so in 2014, when basically every other offering he had was, for lack of a better term, bad:

2014 pitch / wRC+ against
Fastball / 112
Split-change / 65
Cutter / 121
Slider / 109
Curve / 127

We don’t easily have home/road splits on those, but if it’s De La Rosa’s belief that more split-changes will help on the road, maybe that’s not the worst idea. What really stands out are the homer numbers, because he’s somehow managed to give up 20 on the road against only 12 in Colorado, in what’s a nearly identical amount of innings. That’s partially due to 2013’s unsustainably low HR/FB rate, but whatever it is about that split-change at home, it works — he’s allowed only 13 homers on it in Coors Field dating all the way back to 2008.

How about that business about his breaking pitches breaking “too much” away from Coors so that he can’t throw them for strikes? Not that you always want a breaking pitch to be in the zone, of course, but that’s what he indicated the issue was. The data doesn’t really back him up here, actually. Over the last two years, he’s thrown his slider and curve within the PITCHf/x strike zone 29.8% of the time away from home. In Colorado? 25.6%. That’s not’s necessarily the same as being able to put it exactly where he’d want it to be, either, it just doesn’t lend itself to the idea that his breaking pitches are somehow uncontrollable at regular altitudes. Nor, really, does the fact that his swinging strike rate on the pair of pitches has been 10.2% at home, and 11.5% on the road.

I’m not sure we’ve really identified De La Rosa’s secret here, but then again I’m not really sure that should have been the expectation from a few hours spent on a Sunday night. If it were really that easy, then the Rockies wouldn’t be headed into their 23rd (!) year of play still trying to figure out how to put together a successful pitching staff. The simplest answer is that De La Rosa has found the right mix specifically for his unique set of pitches that works in Coors Field, though probably not to the extent shown in 90-inning samples of 2014, where he out-performed (at home) and under-performed (on the road) his FIP by more than a run in both directions.

De La Rosa might be the right pitcher for the right place, almost certainly more valuable to the Rockies than he would be to anyone else. Barring injury, the two-year contract is probably worthwhile. They still should have traded him for Rodriguez, though, if that was real. Definitely should have done that.