Diamondbacks Gameday Thread, #148: 9/14 @ Mets

Roster moves

The Arizona Diamondbacks made the following roster moves:

• Reinstated C Gabriel Moreno from the Paternity List.
• Optioned C Jose Herrera to Triple-A Reno following last night’s game.

I think we’re all glad to see Moreno back in the line-up. This is something which cropped up in the Gameday Thread last night. If you think the team just plays better with him, you’re dead right. When Gabriel Moreno starts this year, the D-backs have gone 49-31. When he doesn’t, they are 27-40. That’s a striking difference, and the success with Moreno stands in sharp contrast to the other main catchers: they’re 18-18 when Jose Herrera starts, and an equally striking - just in a bad way - 8-20 when Carson Kelly starts (he’s also 3-6 when starting for the Detroit Tigers). I figured it was worth looking into these numbers a bit more.

All told, in the 80 Moreno starts, Arizona has scored 358 runs and conceded 338. In the 67 other starts (also including three by Seby Savala) they have scored 320 and conceded 363. Looking at on a per-game basis, this is what we find:
Moreno starts: RS 4.48, RA 4.22
Other starts: RS 4.77, RA 5.42
That’s interesting. The team actually scores LESS runs when Moreno starts, which goes counter to how it “feels”. But that drop is more than countered by a massive decline in ERA when Gaby is behind the dish. This is reflected in the catcher’s ERA for the team this season:

• Gabriel Moreno: 4.04
• Seby Zavala: 5.00
• Carson Kelly: 5.01
• Jose Herrera: 5.48

So, Moreno is the better pitch-caller. Well, hold on a minute. There could well be another explanation. Put it this way, if I was catching Merrill Kelly and Zac Gallen, I’d probably have a better catcher’s ERA than the poor schmuck working with Madison Bumgarner and Zach Davies. Could that be the case here? To find out, let’s look at the stats for each catcher, just in the games where they were working with Kelly and Gallen. Outside of the Kelly/Kelly battery (three starts), we have at least six games for each of the other main three catchers. Though I should mention there are doubts over whether catcher ERA is “meaningful”. Here are the cERAs for each:

• Gabriel Moreno: Kelly 2.59; Gallen 3.07
• Carson Kelly: Kelly 4.76; Gallen 3.55
• Jose Herrera: Kelly 3.86; Gallen 3.60

Particularly with Merrill, it does seem that the results are better when throwing to Moreno that anybody else. The sample size here may well not be enough to be statistically significant, but one factor I immediately can think of, wold certainly play into this. Gabriel Moreno is much better at controlling the running game. Against him, base stealers this year are 31-20. Against everyone else, they’re 49-11. Total Baseball calculated a stolen-base to be worth 0.3 runs, and and caught stealing to be -0.6 runs. This gives Moreno’s arm a value of +2.7 runs, and everybody else’s -8.1 runs. Not enough to explain all the difference, but it’s a start.

The nebulous concept of “intangibles” may feed into this too. We all have colleagues that we like working with, and our resulting productivity will reflect this. If our pitchers like working with Moreno, then their results could similarly be better. There’s no way to quantify or even measure this. We can’t exactly pass a note to Gallen, saying “Do you like Gabby? Yes/No.” But as we enter the final fifteen games of the season, with everything to play for, and Moreno back from a little spell, I would expect Torey Lovullo to try and squeeze every last spot of value from the roster. If Moreno is not starting at least a dozen of these contests, I’ll want to know why.