The MLB regular season continues to wind down, and three games on the slate today carry postseason weight. I have my MLB best bets locked in on Polymarket, where you buy yes or no shares on an outcome instead of laying juice at a sportsbook.
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MLB Best Bets at a Glance Today, Sept. 23, 2026
Here are the three games I have circled to wager MLB odds on tonight:
| Matchup | First Pitch (ET) | TV | My Play |
|---|---|---|---|
| Guardians vs. Red Sox | 7 p.m. | ESPN | Guardians win YES (46¢) |
| Rays vs. Yankees | 7:05 p.m. | Prime Video | Yankees win YES (56¢) |
| Astros vs. Mariners | 10 p.m. | ESPN | Astros win YES |
Guardians vs. Red Sox MLB Best Bets
Guardians vs. Red Sox is a game where the former of these teams still battle for postseason seeding, and that urgency separates these two clubs tonight.
Guardians vs. Red Sox prediction: Guardians win YES (46¢)
- The Guardians' pitching staff leads the majors in strikeout rate with runners in scoring position at 26%, and it leads again in close and late spots at 30%.
- Foster Griffin draws the probable start for Cleveland opposite Sonny Gray, who attacks the zone in a park that punishes one bad pitch.
- Cleveland is a club playing for its life, and I expect them to outwork a Boston ineup managing workload since they have a firm grip on its playoff slot.
Rays vs. Yankees MLB Best Bets
Tampa Bay owns the superior record, yet I tilt the Rays vs. Yankees matchup t toward the home dugout this evening.
Rays vs. Yankees prediction prediction: Yankees win YES (56$)
- Gerrit Cole takes the ball for New York with a 3.63 ERA and 123 strikeouts, and he saves his sharpest work for division opponents.
- Ian Seymour, a lefty, brings a 4.15 ERA into a stadium whose short porch turns routine flies into damage.
- Cole at home against the Rays' fourth starter offers the best risk to reward ratio in the early slate of games.
Note that national windows on Prime Video attract heavy late money. Grab your price early rather than near first pitch.
Astros vs. Mariners MLB Best Bets
The late window on ESPN hands you the cleanest read of the night when the Astros vs. Mariners game begins.
My Astros vs. Mariners prediction: Astros win YES (46¢)
- Seattle ranks dead last in MLB against the run line, cashing just 58 of 156 tries.
- The Mariners sit at 2-70 losses when trailing entering the eighth inning.
- Houston hitters draw walks on 13% of plate appearances with runners in scoring position, the best mark in baseball.
- George Kirby misses bats for Seattle, but the offense behind him lacks the thump to support him.
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