Neither team has announced even their rosters to this point, never mind the starting line-ups. The roster does not have to be turned in to MLB until Wednesday. But we can take a look at how the two teams have performed in general this season, by looking at the production each has obtained from the nine positions on the diamond, and their bullpens.
To do so, I’ve used Baseball Reference’s Wins Above Average, which breaks down the bWAR for every NL team by position. Note it’s above average, and not replacement, so a zero figure means the position has produce at league level. Below, you’ll find the results at each, for both the Rockies and the Diamondbacks (with the exception of the starting pitcher: there we do know the specific players for each side, so I used the individual figure). I’ve noted the “regular” starter at each spot, as the main contributor towards the tally, though this may or may not be who starts there on the day in question.
C. COL (Tony Wolters) -1.8 vs. ARI (Chris Iannetta) -1.4
Neither side has covered themselves in glory here, but the real advantage for the D-backs may not show up in bWAR. Arizona deliberately went out and looked for pitch framing this winter, and Jeff Mathis is ranked eighth-best in the majors there this season, with Iannetta about neutral. Wolters, however, is ninth-worst, and everyone who has caught for Colorado in 2017 grades out as below-average. Edge: Arizona.
1B. COL (Mark Reynolds) -1.8 vs. ARI (Paul Goldschmidt) +3.3
A former D-back goes up against an MVP candidate. While Reynolds has hit thirty home-runs, 70% of those were at Coors, and his value at the plate has been significantly negated by poor defense. The main concern for Arizona will be Goldschmidt’s September struggles. Whether the result of his elbow issue or not, Paul batted just .171 with an OPS of .555 making for once of the worst months of his career. We’ll hope for better. Edge: Arizona
2B. COL (D.J. LeMahieu) +0.2 vs. ARI (Brandon Drury) -0.9
The 2016 batting champ was an All-Star this year, and although his OPS dropped by 128 points compared to the previous season. he was still a solid producer. It will be interesting to see if Arizona adopts the same extreme “LeMahieu shift” they used on occasion in the regular season, almost daring him to pull the ball. The D-backs hoped Drury would seize the position this season - that hasn’t worked out quite as they wanted. Edge: Colorado
3B. COL (Nolan Arenado) +4.8 vs. ARI (Jake Lamb) -0.7
The yawning chasm at first is mirrored, albeit in the other direction, at the hot corner, where Arenado has put up MVP numbers again on offense, combined with Gold Glove caliber defense. It’s in contrast to Lamb for the D-backs who has struggled badly, both in the second half and against lefties in general. The latter is to the extent that, if the Rockies had gone with Kyle Freeland, Lamb might not even have started. Edge: Colorado.
SS. COL (Trevor Story) +0.3 vs. ARI (Ketel Marte) -0.7
Story may have had a bit of a sophomore slump, batting only .239 and leading the league in strikeouts, with 191. But he hit .286 with three home-runs at Chase Field this season, and his OPS of 1.004 leads all the Rockies there. The D-backs aren’t likely as poor as this overall number suggests, with Marte making a strong second-half case for an everyday role next year. He did have to leave Sunday’s finale early; according to Torey Lovullo, he’s okay. Edge: Colorado
LF. COL (Gerardo Parra) -2.0 vs. ARI (David Peralta) -2.4
Both sides have seriously underperformed here, getting much less production from expensive signings (Ian Desmond and Yasmany Tomas respectively) than they would like. Hence they have largely turned to left-handers Parra and Peralta, who will likely start Wednesday’s contest. The Arizona player has been better, with 2.5 bWAR over 577 PA, compared to Parra’s 0.9 bWAR in 426 PA. Edge: Arizona
CF. COL (Charlie Blackmon) +3.5 vs. ARI (A.J. Pollock) +0.7
Blackmon finished the season with a 1.000 OPS, tied with Arenado for the team lead with 37 homers, and almost seems wasted hitting in the Colorado lead-off spot. He hit only .182 at Chase with a .473 OPS and a 12:1 K:BB ratio, so the D-backs seem to have a good approach. While Pollock hasn’t had a bad season, overall, it was again disrupted by injury, and lacked consistency. Could hit anywhere from first to seventh. Edge: Colorado
RF. COL (Carlos Gonzalez) -2.5 vs. ARI (J.D. Martinez) +1.9
If Peralta has actually had most playing time here for the Diamondbacks, we know who will be there on Wednesday: the second-half MVP of the National League, hitting .302 with 29 HR in only 62 games. CarGo had a really good September, batting .377 with a 1.250 OPS: it just goes to show how awful the rest of his season had been, that he is still below replacement level (-0.2 bWAR). Edge: Arizona
SP. COL (Jon Gray) 3.2 bWAR vs. ARI (Zack Greinke) 6.0 bWAR
Gray missed close to two and a half months with a stress fracture in his foot, and has anchored the Rockies’ rotation since his return, going 10-4 with a 3.58 ERA. Three of those starts were against Arizona, where he is 2-1 with a 3.50 ERA. Perhaps of note, he won both games in Chase Field. The current Diamondbacks have a .780 OPS against him, with Peralta and Pollock the best among those with more than half a dozen PAs. At the other end, Goldschmidt is 0-for-11 with five strikeouts.
Zack led the D-backs with a 17-7 record and 3.20 ERA, giving their team their first six bWAR season since Dan Haren in 2009. The Rockies will be quite familiar with Greinke, as he started five times against them this season, going 2-1 with a 3.41 ERA. At Chase, he was 1-0 in three starts, ERA 3.15. Colorado collectively has a .732 OPS vs. Greinke, led by Gonzalez’s 1.140 OPS. Among the likely Rockies’ starters, Parra’s .598 OPS is the lowest figure, thanks to just one walk and one extra-base hit in 44 PA. Edge: Arizona
RP. COL 2.1 vs. ARI 2.3
Perhaps surprisingly, the teams are #2 and #1 in the National League for relief pitching by this metric. So I doubt either manager will have any hesitation in going to the bullpen if their starter struggles on Wednesday. Interestingly, both teams have exactly the same record, 74-6, when leading after six innings, and are very similar thereafter, which suggests that whoever had the lead late, is going to cling onto it. The D-backs do have more late comeback victories though: eight when trailing at the end of the seventh, compared to the Rockies’ three. Edge: even.
Conclusion
These are evenly matched teams, with both have areas of strength where they are clearly superior to their opponent. The game being played at Chase Field should help the D-backs, who are 52-29 there, while the Rockies are 41-40 on the road. Arizona also took the season series, winning eleven of the nineteen games. However, the ten contests in Phoenix were evenly split, each side winning five. I think the D-backs should be considered the favorites - and Las Vegas appear to concur, going by the odds I’ve seen. However, it’s not overwhelming, and the result will simply come down to who plays best on the night, and perhaps who makes fewest mistakes.