Walk-Off Wagers: MLB Best Bets Today (Predictions for Cubs-Pirates, Guardians-Tigers, Blue Jays-Rays)

Breaking down the best bets for the MLB action on Wednesday, Sept. 17, including a pick for the Blue Jays-Rays matchup.

Toronto Blue Jays starting pitcher Kevin Gausman has led his team to a 7-3 record in his starts since the All-Star break. / John E. Sokolowski-Imagn Images

There are plenty of afternoon games in Major League Baseball on Wednesday for bettors to get involved in the action all day long as the playoff race heats up.

Two teams chasing a wild card spot in the National League – the Cincinnati Reds and St. Louis Cardinals – face off in one of the early games on the slate while the New York Mets continue their series with the San Diego Padres, a battle between two teams in wild card spots for now. 

On Wednesday, I’m targeting a few matchups for our best bets here at SI Betting, including an upset pick in the Cleveland Guardians-Detroit Tigers matchup. 

Let’s examine the odds for each game as well as the breakdown for these best bets. 

MLB Best Bets for Wednesday, Sept. 17

Odds via DraftKings Sportsbook

• Pittsburgh Pirates First 5 Innings +0.5 (-120) vs. Chicago Cubs
• Cleveland Guardians Moneyline (+123) vs. Detroit Tigers
• Toronto Blue Jays Moneyline (-131) vs. Tampa Bay Rays

Pittsburgh Pirates First 5 Innings +0.5 (-120) vs. Chicago Cubs

The Pittsburgh Pirates and Chicago Cubs will get things started with an afternoon matchup on Wednesday, and I’m actually fading the Cubbies early even though they’ve won three games in a row.

Lefty Matthew Boyd is on the mound for Chicago, and he’s struggled as of late, allowing four or more runs in three of his last four starts while posting a 4.37 ERA since the All-Star break. During that 10-game stretch, Boyd has led the Cubs to just a 3-7 record.

He’ll take on Pirates righty Johan Oviedo on Wednesday, and Oviedo has looked good in his return from injury, posting a 2.81 ERA across six starts – reaching the fifth inning in four of those outings.

While the Pirates struggle to score, I don’t mind taking them to be tied or leading through five frames on Wednesday. Boyd has 3.41 ERA in the first inning and a 3.72 ERA in the third inning this season, so it’s likely that he’ll allow at least one run early on in this outing.

Meanwhile, Oviedo has not given up more than two runs in a single outing in 2025.

I like the Pirates at home to keep this game close early. 

Cleveland Guardians Moneyline (+123) vs. Detroit Tigers

Can you say upset?

The Cleveland Guardians are surging right now in the AL Central, winning five games in a row and nine of their last 10 to pull within 5.5 games of the Detroit Tigers for the division lead. On top of that, Cleveland is just 2.5 games out of a playoff spot in the AL.

On Wednesday, the Guardians have Gavin Williams (3.16 ERA) on the mound against Detroit veteran Jack Flaherty (4.69 ERA).

If there’s one concerning stat to look at in this matchup, it’s the Tigers’ record with Flaherty on the mound in 2025. This season, Detroit is just 9-20 with the righty on the bump, and Flaherty has a 5.14 ERA in eight starts since Aug. 1. 

Williams hasn’t been lights out in 2025 – he ranks in the 31st percentile in expected ERA – but his actual numbers haven’t caught up to that so far. Williams has a 2.28 ERA in 10 starts since the All-Star break, and I’m starting to buy that he may avoid any regression to what his advanced numbers say in 2025. 

Overall, the Guardians are 15-14 in Williams’ outings, including a 7-3 mark over his last 10 starts.

With Cleveland on a huge winning streak and back in the playoff mix, I think it’s worth a bet as an underdog with this pitching matchup on Wednesday. 

Toronto Blue Jays Moneyline (-131) vs. Tampa Bay Rays

The Toronto Blue Jays have won six games in a row and are in the driver’s seat in the AL East heading into the third game of a four-game set against the Tampa Bay Rays on Wednesday night.

This bet is pretty simple with the Jays set as small road favorites, as Tampa Bay is five games under .500 overall and just 38-38 at home in the 2025 season.

Kevin Gausman (3.44 ERA) is on the mound for the Jays, and he’s been absolutely dominant as of late. Gausman is coming off a two-hit shutout against the Houston Astros, and he’s posted an ERA of 2.25 in 10 starts since the All-Star break.

During that 10-game stretch, Gausman has allowed one or fewer runs in six outings.

He’ll take on Ian Seymour (2.95 ERA) on Wednesday, but I’m not buying Tampa to win this game. Seymour has made just three starts this season, and the Rays will likely rely heavily on their bullpen in this matchup.

Right now, Gausman is one of the hottest pitchers in the AL, and the Jays seem poised to lock up a division crown. I’ll gladly back them at this price on Wednesday night.

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Odds refresh periodically and are subject to change.

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