The American League Division Series continues Wednesday afternoon as the Seattle Mariners look to finish off the Detroit Tigers in Game 4 at Comerica Park. Seattle holds a 2–1 series lead after Detroit extended the matchup with a gritty win in Game 3. The Tigers turn to former No. 1 pick Casey Mize to keep their season alive, while the Mariners counter with Bryce Miller, whose electric fastball has been both a weapon and a risk this year. With Seattle one win from advancing and Detroit fighting to stay alive, this elimination-pressure game sets up as a perfect clash of youth, nerves, and execution — and the market reflects that, opening close to a pick’em.
Quick Picks:
- Best Bet: Under 8.0 Runs (-115) ★★★★☆
- Top Prop: Casey Mize Over 5.5 Strikeouts (+105) ★★★★☆
- Value Play: Seattle Mariners ML (-108) ★★★☆☆
Seattle Mariners vs Detroit Tigers Betting Odds & Latest Line Movement
| Market | Seattle Mariners | Detroit Tigers |
|---|---|---|
| Moneyline | -108 | -112 |
| Run Line | -1.5 (+165) | +1.5 (-195) |
| Total | Over 8.0 (-105) | Under 8.0 (-115) |
Opening Line: Mariners -105, Tigers -115, Total 8
Sharp Money Analysis: Where Pro Bettors Are Placing Their Wagers
Early action has leaned slightly toward Seattle after opening near even money, signaling some sharp confidence in the Mariners’ ability to close out the series. Detroit’s Game 3 win has drawn public buy-in, with roughly 60% of tickets on the home side, but respected money remains skeptical of Mize’s workload under postseason pressure. The total has seen a small tick toward the Under, reflecting both pitchers’ tendency to induce weak contact and Comerica Park’s forgiving dimensions. With both managers quick to use high-leverage arms, the sharper side has been the Under since open.
Pitching Matchup: Bryce Miller vs Casey Mize
Seattle Mariners: Bryce Miller (RHP)
- Season line: 4–6, 5.68 ERA, 1.34 WHIP, 74 K in 84 innings
- Fastball-heavy approach (four-seamer 65% usage) averaging 96.1 mph
- Has struggled on the road (6.02 ERA, .281 opponent average)
- Strong flyball profile fits Comerica’s big outfield — fewer home run threats
- Allowed two runs or fewer in three of his last five starts
Detroit Tigers: Casey Mize (RHP)
- Season line: 14–6, 3.87 ERA, 1.18 WHIP, 139 K in 174 IP
- One of MLB’s most consistent strike-throwers (5.1 K/BB ratio)
- Home ERA: 3.22 with opponents batting just .224 at Comerica Park
- Limited Mariners to one run over seven innings in their May meeting
- Has thrown at least six innings in 10 of his last 12 starts
Edge: Detroit on paper, but Seattle’s bullpen depth gives the Mariners a path to steal it late. Mize is the steadier arm, yet Miller’s flyball profile could benefit in Comerica’s deep dimensions.
Bullpen Breakdown
Seattle’s bullpen remains the difference-maker in this series. Andrés Muñoz (39 saves) continues to anchor a unit that’s allowed just two runs over 9.1 postseason innings. Gabe Speier and Matt Brash have been key in bridging to Muñoz, giving Seattle a decisive late-game edge. Detroit’s bullpen, meanwhile, has looked overextended after logging 11 innings over the last two games. Will Vest and Kyle Finnegan share closing duties, but both have struggled with command when pitching on back-to-back days. If this game is tight in the late innings, Seattle holds the advantage.
Key Betting Trends & Team Statistics That Matter
- Seattle leads series 2–1 entering Game 4
- The Under is 6–2 in their last eight meetings
- Seattle has held opponents to three or fewer runs in 8 of its last 10 games
- Detroit is 42–35 at Comerica Park this year
- Tigers are 5–1 in Mize’s last six home starts
- Mariners’ bullpen has a 1.94 ERA this postseason
- Bryce Miller has allowed 2+ homers in only one of his last eight starts
- Seattle is 9–4 in its last 13 postseason road games
Munoz’s Playoff Dominance: The Ultimate Equalizer
Andrés Muñoz continues to be a weapon for the Mariners, converting both save opportunities with overpowering efficiency. His 100-mph velocity and sweeping slider have generated a 46% whiff rate this postseason. Detroit’s lineup has struggled against elite velocity — hitting just .198 against pitches 97 mph or higher. If the Mariners lead entering the ninth, Muñoz makes them nearly automatic. His +160 “To Record a Save” prop carries strong value once again.
Comerica Park Factor: How It Impacts Game 4
Comerica Park ranks 6th in MLB in overall run factor (1.039) but only 25th in home run factor (0.928). The vast outfield helps pitchers like Miller, who rely heavily on elevated fastballs. However, it can also inflate doubles and triples if command wavers. October weather in Detroit is expected around 64°F with light winds — slightly suppressing power. Expect contact-heavy baseball, long at-bats, and late-inning decisions to define this one. The park dynamics support the Under, especially with two right-handers who throw strikes and avoid free passes.
Expert Prediction & Best Bets for Mariners-Tigers Game 4
Primary Play: Under 8.0 Runs (-115)
Comerica’s spacious layout, the postseason setting, and both managers’ quick hooks favor another low-scoring contest. Both Mize and Miller match up well with their opponents’ weaknesses, and bullpen usage will be aggressive. Runs will come from manufacturing rather than power — making 8 runs too high. Play it down to 7.5.
Secondary Play: Seattle Mariners ML (-108)
Seattle’s bullpen depth and experience in tight games make them the sharper side. Miller’s ability to keep the ball in the park, paired with Munoz’s dominance late, should carry the Mariners over the line in a close one.
Prop Play: Casey Mize Over 5.5 Strikeouts (+105)
Mize’s slider and splitter both tunnel well against Seattle’s right-handed-heavy lineup, which has the AL’s third-highest K-rate versus righties (24.1%). With his efficiency and consistent six-inning workload, this prop offers solid value at plus money.
Player Props Worth Targeting in Game 4
| Player | Prop | Odds | Rating |
|---|---|---|---|
| Casey Mize | Over 5.5 Strikeouts | +105 | ★★★★☆ |
| Bryce Miller | Under 2.5 Walks Allowed | -140 | ★★★☆☆ |
| Andrés Muñoz | To Record a Save | +160 | ★★★★☆ |
| Riley Greene | Over 1.5 Total Bases | +120 | ★★★☆☆ |
| Julio Rodríguez | To Record an RBI | +135 | ★★☆☆☆ |
Final Thoughts: Mariners’ Edge in the Pen Could Seal the Series
Detroit has shown fight, but Seattle’s pitching structure remains the deciding factor. Mize should give the Tigers length, but the bullpen gap looms large — and Miller’s fastball command paired with Comerica’s dimensions fits the Under narrative perfectly. Expect a tight, strategic game where Seattle’s discipline and late-inning arms give them the edge to close out the series.
Score Prediction: Seattle Mariners 4, Detroit Tigers 3
