Another day, another blockbuster. I literally went “ohhh my God” when I read the news on Rotoworld. Obviously, you know by now that Paul Goldschmidt was traded to the Cardinals. Was he on the block? I had no idea, though admittedly I pay little attention to speculation and rumors. Let’s try to figure out how the switch in home parks might affect his performance.
Before sharing the relevant park factors, I should note that because of the introduction of the humidor, I absolutely had to find 2018 park factors that weren’t rolling three or five year factors. I was able to find one set, on Baseball Prospectus. So the following factors are from that site. They passed the sniff test as the factors we would expect were lower this year than the past.
Let’s start with the various base hits. Chase Field (Arizona) marginally suppressed singles previously, but the humidor actually made the park slightly more favorable, bringing it up to neutral. However, that’s still below Busch Stadium (St. Louis), which inflates singles by 4%. So all else being equal, the park switch would boost Goldschmidt’s BABIP ever so slightly.
Doubles factors are nearly identical, with both parks suppressing these hits. Onto triples, where we find that Chase was the second best park in baseball for them. That’s quite the massive boost hitters receive. Busch also increases triples, but not by nearly the same degree. Of course, we’re not really concerned with triples, given that Goldy has hit only 19 in his career, though he is coming off a career high of five. At most, maybe he loses one triple with the move, which is essentially meaningless.
Another potentially dramatic change that might get overlooked is the home run factors. Before the humidor, Chase was one of the more favorable home run parks in baseball. But the humidor killed that and now it actually suppresses homers. Still, it doesn’t do so at nearly the same rate as Busch does. In fact, Busch held the fifth lowest right-handed home run park factor in baseball this season. That doesn’t bode well for Goldschmidt.
In 2018, it appears that Goldy was significantly hampered by the introduction of the humidor, as his home HR/FB rate was just 16.2% versus a 26.6% mark in away parks. For his career, excluding 2018, his home/road HR/FB rate splits were actually nearly identical, which is a bit surprising given how favorable the park is for homers and the fact that hitters tend to hit better and for more power at home. Goldy has been extraordinarily consistent in his HR/FB rate, as he has maintained a mark between 19% and 24.8% every season since 2013. That’s pretty amazing.
If we account for the fact that Goldy will only play half his games at home, then the move to St. Louis would only reduce his HR/FB rate by about 3%, which means that if we assumed a HR/FB rate matching his career of 20.7%, his mark would merely drop to 20%. So, noise and randomness is going to have far more of an effect on his HR/FB rate than the park switch.
Moving along to the batted ball types, we find that Chase suppressed pop-ups, while Busch is neutral. For his carer, Goldschmidt has been a bit better than the average hitter at avoiding pop-ups, but he’s posted his three highest seasons in the last three years. This is a fluky stat though that really jumps around, so again, the park effects aren’t going to drive this rate much.
Finally, we find that the humidor has made Chase a completely neutral park, while Busch is slightly favorable for pitchers. Clearly, the park switch is a net negative for Goldschmidt, but not enough to drop him by more than a buck or two.
The biggest question revolves around his stolen bases. After swiping at least 18 bases for three straight seasons, he stole just seven, his lowest mark of any full season. Though it’s not fair to simply compare stolen base totals between the two teams to help determine whether he’ll run more, less, or the same with the Cardinals, it’s the easiest way for now. The Cardinals ranked 26th in baseball in steals last year, versus 14th for the Diamondbacks, so there’s seemingly less a chance of a rebound back to the double digits. That could be the difference between getting back to first round value or earning third or fourth round value.
Mike Podhorzer is the 2015 Fantasy Sports Writers Association Baseball Writer of the Year. He produces player projections using his own forecasting system and is the author of the eBook Projecting X 2.0: How to Forecast Baseball Player Performance, which teaches you how to project players yourself. His projections helped him win the inaugural 2013 Tout Wars mixed draft league. Follow Mike on Twitter @MikePodhorzer and contact him via email.