The Colorado Rockies and Arizona Diamondbacks close their three-game series on Wednesday afternoon at Chase Field, and the market sees a clear separation. Arizona sits as a heavy home favorite at -182 on the moneyline, with the Rockies a +150 road underdog. Colorado did steal Tuesday’s game 3-2, so this finale is not the formality the price suggests. Below we break down the pitching matchup, the odds, and the two plays we like best — starting with a way to back the favorite without paying full freight.
Last Updated: Wednesday, August 12, 2026
Colorado Rockies vs. Arizona Diamondbacks — Time & How to Watch
| Where | Chase Field, Phoenix, Arizona |
| When | August 12, 2026 — 3:40 PM ET |
| TV | Dbacks.TV and Rockies.TV |
Colorado Rockies vs. Arizona Diamondbacks Betting Preview
Pitching frames this one, and neither starter profiles as a stopper. Arizona hands the ball to right-hander Merrill Kelly, who carries an 8-9 record and a 4.88 ERA. Kelly has generally worked around five innings in his recent outings, keeping the damage manageable but rarely overpowering a lineup. Colorado counters with Ryan Feltner, who is 4-6 with a 5.71 ERA and has been one of the more hittable arms in the rotation. On paper Arizona holds the edge. Still, this is a meeting of two below-average starters, not an ace against a soft-tosser.
The stakes are lopsided. Arizona is 64-56 and holds a National League wild-card spot, chasing the Dodgers in the NL West while banking wins against the bottom of the standings. Colorado is 46-73, buried in the division and far weaker away from Coors Field, where its offense loses much of its altitude boost. However, the Rockies flashed life on Tuesday, grinding out a 3-2 win after dropping the opener 9-0 — a series we also sized up in our Tuesday Rockies-Diamondbacks preview. That split is a reminder that even a struggling club can hang around for nine innings.
Colorado Rockies vs. Arizona Diamondbacks Odds
| Run Line | Moneyline | Total | |
|---|---|---|---|
| Rockies | +1.5 (-135) | +150 | U 9.5 (-120) |
| Diamondbacks | -1.5 (+115) | -182 | O 9.5 (+100) |
Odds accurate as of Wednesday, August 12, 2026 via TheSpread.com. Odds change, get the latest MLB Odds – Futures – Props
Colorado Rockies vs. Arizona Diamondbacks — Who Is the Public Betting?
| Rockies | 10% | 90% | Diamondbacks |
See the latest MLB Public Betting Splits and make smarter wagers!
Rockies vs. Diamondbacks Prediction — Can Colorado Keep It Close on the Road?
The case for laying the run line with Arizona starts with the talent gap and the price. The Diamondbacks are the better team at nearly every level here, and they draw the National League’s weakest road club on an afternoon when Colorado hands the ball to a 5.71-ERA starter. Arizona already showed what a mismatch can look like, hanging a 9-0 number on the Rockies in Monday’s opener. At +115, the run line pays plus money to have the home team win by two or more, which is a cleaner value proposition than laying -182 on the moneyline.
The counter-case is real, though. Home favorites are structurally awkward on the run line, because a lead after the top of the ninth ends the game before Arizona can pad the margin, and one-run wins do not cover -1.5. Colorado just proved it can play this exact Diamondbacks team to a single run. On top of that, Kelly’s habit of exiting around the fifth inning hands the outcome to the bullpen earlier than you would like. This is a lean rather than a lock, and the margin is the whole question.
The Pick: Diamondbacks Run Line -1.5 (+115)
Rockies vs. Diamondbacks Prediction — Will the Desert Air Feed the Scoreboard?
The total is the second angle worth a look, and the pitching points toward runs. Both starters carry ERAs near or above 5.00, and Chase Field’s retractable roof and hitter-friendly reputation give the ball room to travel when the offenses connect. With Feltner’s hittable profile and Kelly rarely working deep, both bullpens should be involved well before the finish. That is usually where totals get nudged over the number.
There is a clear reason to hesitate. The first two games of this series both stayed under 9.5, with the teams combining for nine runs on Monday and five on Tuesday, so the recent scoring has not matched the shaky ERAs. A 9.5 total is a fair number rather than a soft one. Getting plus money on the over is the tiebreaker for us, but this is a modest lean built on the starters, not a runaway edge.
The Pick: Over 9.5 (+100)
Final Thoughts and Bonus Angle
Wednesday’s finale comes down to whether Arizona’s talent edge shows up on the scoreboard or whether Colorado keeps grinding out close games the way it did on Tuesday. Watch Kelly’s pitch count early. If he can navigate the middle innings without leaning hard on the bullpen, Arizona’s path to a multi-run win gets much smoother. If Feltner settles in the way he sometimes does, the under becomes live and the run line tightens. You can find more of our latest MLB best bets across the schedule for additional angles.
To recap, here are our two plays for the rubber match: Diamondbacks Run Line -1.5 (+115) and Over 9.5 (+100). Both lean on Arizona’s bats producing, so bettors who want to spread the risk can take them separately rather than as a single package.
MLB Rockies vs. Diamondbacks FAQ: Wednesday August 12, 2026
What time does the Rockies vs. Diamondbacks game start?
First pitch is set for 3:40 PM ET on Wednesday, August 12, 2026, at Chase Field in Phoenix. This is the afternoon finale of a three-game series, an earlier start than the two night games that opened the set on Monday and Tuesday.
What channel is the Rockies vs. Diamondbacks game on?
The game airs on the teams’ regional streaming feeds, Dbacks.TV in Arizona and Rockies.TV in Colorado, with an out-of-market option available through MLB.TV. Local availability depends on your region, so viewers outside the two home markets should check their MLB.TV blackout rules before the first pitch.
Who is pitching for the Diamondbacks today?
Merrill Kelly is the probable starter for Arizona, carrying an 8-9 record and a 4.88 ERA into the outing. The right-hander has generally worked around five innings in his recent starts. Colorado counters with right-hander Ryan Feltner, who is 4-6 with a 5.71 ERA this season.
Where are the Rockies and Diamondbacks playing today?
The teams play at Chase Field in downtown Phoenix, Arizona, the Diamondbacks’ home ballpark. Chase Field features a retractable roof that lets the club close the stadium and control conditions during the desert summer, and it has long carried a hitter-friendly reputation among big-league parks.
Who won the last meeting between the Rockies and Diamondbacks?
Colorado won the most recent meeting, taking Tuesday’s middle game of the series 3-2 on August 11, 2026. That result evened the three-game set at one win apiece after Arizona rolled to a 9-0 victory in Monday’s opener, setting up Wednesday’s rubber match.