Rockies vs. Diamondbacks prediction: Why Arizona is favored to win Wednesday's MLB matchup [8/12/2026]

MLB action continues on Wednesday at 3:40 PM ET as the Colorado Rockies take on the Arizona Diamondbacks at Chase Field.

The Diamondbacks will have Merrill Kelly (8-9, 4.88 ERA) as their starting pitcher, while the Rockies have opted for Ryan Feltner (4-6, 5.71 ERA).

Dimers' proven MLB model projects the Diamondbacks as the most likely winner in this Rockies vs. Diamondbacks prediction.

This article offers an expanded analysis of Wednesday's matchup, including best bets and picks.

Rockies vs. Diamondbacks prediction: Who will win and cover?

Using innovative machine learning and statistical analysis, we have simulated the outcome of Wednesday's MLB game between the Rockies and Diamondbacks, forming part of our MLB predictions coverage.

Our leading predictive model gives the Diamondbacks a 63.9% chance of defeating the Rockies.

According to our model, the Rockies (+1.5) have a 52.8% chance of covering the run line, while the over/under total of 9.5 runs has a 55.9% chance of going over,.

Rockies vs. Diamondbacks odds [8/12/2026]

We have sourced the best MLB odds in America for this game, which are listed here:

• Run Line: Rockies +1.5 (-125) / Diamondbacks -1.5 (+122)
• Moneyline: Rockies +170, Diamondbacks -164

All odds are correct at the time of publication and are subject to change.

Rockies vs. Diamondbacks picks and best bet

After matching our predictions against the best current odds, we can reveal our picks for each of the major markets in this matchup. Plus, find our best bet for the game below:

• Run line: Diamondbacks -1.5 @ +122 via DraftKings
• Moneyline: Diamondbacks @ -164 via Bet365
• Total: Over 9.5 @ +115 via DraftKings

According to our MLB best bets, the top play to make on this game is Over 9.5 total runs.

These picks are based on our probabilities matched against the implied probabilities from the sportsbook odds.

Rockies vs. Diamondbacks game-day updates and essential details

Wednesday's MLB game between the Diamondbacks and Rockies at Chase Field is scheduled to begin at 3:40 PM ET.

• Who: Colorado Rockies vs. Arizona Diamondbacks
• Date: Wednesday, August 12, 2026
• Time: 3:40 PM ET/12:40PM PT
• Venue: Chase Field

Conclusion

We predict the Diamondbacks, with a 63.9% win probability, will likely beat the Rockies in Wednesday's MLB matchup.

Additional tools and information for betting safely can be found in our Responsible Gambling hub.