MLB Predictions and Moneyline Picks for Tuesday, Aug. 18

Colby Marchio - Contributor at Covers.com
Colby Marchio • Betting Analyst 7+ years betting experience
Updated: Aug 18, 2026 , 01:31 PM ET • 4 min read

Tuesday's moneyline predictions feature a ton of underdogs with some bite, while also backing the Cardinals again at a reasonable price.

Jordan Walker St. Louis Cardinals MLB
Photo By - Reuters Connect. St. Louis Cardinals right-fielder Jordan Walker celebrates with catcher Ivan Herrera after hitting a solo home run.

Full slate Tuesday is back!

Here are my MLB moneyline predictions for tonight’s schedule, featuring a plethora of underdogs and the Cardinals at a discount.

Before we dive in, be sure to check out all of our MLB picks on Tuesday, Aug. 18.

MLB moneyline picks for Aug. 18

Matchup Pick
Yankees Yankees
vs
Orioles Orioles
Orioles
+104
Tigers Tigers
vs
Pirates Pirates
Tigers
+135
Giants Giants
vs
Guardians Guardians
Giants
-182
Cardinals Cardinals
vs
Reds Reds
Cardinals
-111
Blue Jays Blue Jays
vs
Rays Rays
Rays
-125
Marlins Marlins
vs
Phillies Phillies
Marlins
+199
Diamondbacks Diamondbacks
vs
Red Sox Red Sox
Red Sox
-156
Padres Padres
vs
Mets Mets
Padres
-106
Athletics Athletics
vs
Royals Royals
Royals
-150
Braves Braves
vs
Twins Twins
Braves
-120
Mariners Mariners
vs
Brewers Brewers
Mariners
+156
Nationals Nationals
vs
Rangers Rangers
Rangers
-141
White Sox White Sox
vs
Cubs Cubs
White Sox
+160
Angels Angels
vs
Astros Astros
Astros
-153
Dodgers Dodgers
vs
Rockies Rockies
Dodgers
-178

Prices courtesy of Polymarket as of 8-18.

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Expert MLB moneyline picks for Aug. 18

Yankees vs Orioles: Orioles (+104)

Orioles win probability: 49%

Yes, let's back an offense with a 76 wRC+, .284 wOBA, and .635 OPS over its last 21 games instead of a team sporting a 137 wRC+, .374 wOBA, and .855 OPS.

Tonight will be Carlos Rodon's first game since June 28 too, yet he's still a $1.06 favorite.

Please.

Take the Orioles as a dog. Take the scorching-hot offense.

Tigers vs Pirates: Tigers (+135)

Tigers win probability: 42%

It's pretty perplexing why the Tigers are such heavy dogs this evening against Braxton Ashcraft and the Pirates. Detroit's offense has been extremely consistent over its last 21 games, posting a 130 wRC+, sub-20% strikeout rate, and .804 OPS.

Meanwhile, the Pirates have been showing some signs of heating up over their last six games. But accross their last 21, they own just a 91 wRC+ and .656 OPS.

Keider Montero has been solid on the road this season, and at +135, the Tigers offer a ton of value.

Giants vs Guardians: Guardians (-182)

Guardians win probability: 64%

The Guardians' offense has not been too lively lately, posting a 95 wRC+ over their last six games. However, they draw Carson Whisenhunt, who has been absolutely hammered in his last three starts, posting an 8.03 ERA and 2.11 WHIP while allowing nearly a 50% hard-hit rate. He should be exactly what this Guardians offense needs to get back on track.

Foster Griffin hasn't been great in his last few outings, but he's been showing more consistency than Whisenhunt.

Cardinals vs Reds: Cardinals (-111)

Cardinals win probability: 52%

I'm Not sure why the Cardinals are so cheap today, but it's them or nothing in this spot. The Reds own a 75 wRC+ over their last 12 games while striking out at a 27% clip. Meanwhile, the Cardinals have posted a 111 wRC+, 19.9% strikeout rate, and 9.4% walk rate over that same stretch.

St. Louis sends Kyle Leahy to the mound this evening, and he owns a 2.25 ERA over his last three starts. He's also done a good job limiting hard contact and walks during that stretch.

On the other side, the Reds send out Andrew Abbott, who owns a 6.19 ERA across his last three starts.

Blue Jays vs Rays: Rays (-125)

Rays win probability: 56%

If Jose Soriano is the reason we're getting the Rays at -125, thank him now. The Blue Jays right-hander may own a 1.15 ERA over his last three outings, but his expected ERA is nearly 5.00. He's also walked nearly 13% of batters while allowing a 47.6% hard-hit rate during those starts.

The Blue Jays' bats continue to stay cold, while the Rays are one of the most consistent teams in baseball.

Pay the juice. Take the Rays.

Marlins vs Phillies: Marlins (+199)

Marlins win probability: 34%

This is strictly a moneyline article, so we're not paying $2.03 on a random Tuesday in August. Plus, with how poorly Zack Wheeler has pitched against lefties in his last few starts, the Marlins' offense could be in line for a big night.

Over his last three starts against lefties, Wheeler owns a 5.84 ERA, 1.62 WHIP and 10.34% walk rate.

Tyler Phillips will likely follow Cade Gibson this evening. Phillips has not exactly been able to stop a nosebleed, but in this spot, it will be the Marlins' offense that leads this team to a win.

Diamondbacks vs Red Sox: Red Sox (-156)

Red Sox win probability: 61%

Death. Taxes. Fade Merrill Kelly on the rubber.

The Diamondbacks right-hander has been awful all season long, and he owns a 6.89 ERA, 6.02 xERA, and 1.72 WHIP over his last three starts. Ranger Suarez hasn't been any better, but when it comes to consistency, Kelly has been consistently worse all year.

Paying the $1.56 juice is a concern, but the Red Sox should be able to get after Kelly early and often.

Padres vs Mets: Padres (-106)

Padres win probability: 52%

Even with tight pants Robbie Ray on the mound for the Padres this evening, they're still the play.

San Diego's bats have been on fire, while the Mets have gone cold in their last six games. Mets southpaw Zac Thornton sports a 4.78 xERA in his last five starts, and the Padres' offense should be able to exploit that this evening. 

Athletics vs Royals: Royals (-150)

Royals win probability: 60%

I hate telling the good people who read this article every day to lay $1.50 on the 2026 Kansas City Royals to win a baseball game. However, when Athletics right-hander Jack Perkins owns an 8.25 ERA over his last five starts and an 11.48 ERA across his last three, how on earth could the Athletics get any love in this matchup?

Bobby Witt Jr., Jac Caglianone, and Vinnie Pasquantino should be more than capable of sparking some life into this Royals offense tonight.

Braves vs Twins: Braves (-120)

Braves win probability: 55%

Death. Taxes. Fade Zebby Matthews on the bump.

The Twins starter owns a 6.00 ERA and 1.53 WHIP while allowing a staggering 63% hard-hit rate and 9.3% barrel rate over his last three starts.

The Braves boast one of the highest-rated offenses on the day, according to the Batters-Box model. Tyler Mahle takes the mound for them while owning a 2.83 ERA and 0.94 WHIP in his last five games. He should be able to cool down the Twins' hot bats. 

Mariners vs Brewers: Mariners (+156)

Mariners win probability: 39%

There may be some value in the Mariners this evening, as Bryce Miller has been a little off in his last five starts, but his underlying metrics point toward improvement. Additionally, Seattle's bats have finally woken up. Over their last six games, they own a 120 wRC+, .766 OPS, and .182 ISO.

On the other end, the Brewers' offense has gone cold, owning a 76 wRC+, .282 wOBA and .605 OPS.

At +156, the Mariners are a good look.

Nationals vs Rangers: Rangers (-141)

Rangers win probability: 58%

With how well Cal Quantrill has been performing, it's going to be tough to force a fade against him going forward. The veteran owns a 2.21 ERA, 0.98 WHIP, and 22% strikeout rate over his last five starts.

Washington has been scuffling over its last few games, which could allow Quantrill to take advantage of the team's most significant flaws, which are strikeouts and minimal hard contact.

White Sox vs Cubs: White Sox (+160)

White Sox win probability: 38%

Eric Fedde hasn't been the greatest in his last few outings, or this entire season. However, there's one thing the Chicago White Sox have yet to do this season: Get down on themselves. They have taken a lot of losses on the chin, only to get right back up and earn their revenge.

For the Cubs to win after an emotional walk-off at -163 is a little much, so take the underdog to bounce back.

Angels vs Astros: Astros (-153)

Astros win probability: 60%

The Astros are always due to pop off with Yordan Alvarez in their lineup. Sure, they own a wRC+ under 90 over their last 12 games. However, the Angels have been worse during that stretch, and with right-hander George Klassen on the mound, the Astros can capitalize.

Klassen has been allowing almost a 20% barrel rate this season. He owns a 6.14 ERA and 2.18 WHIP overall in 2026.

Pay the juice and take the Astros.

Dodgers vs Rockies: Dodgers (-178)

Dodgers win probability: 64%

The price for the Dodgers should probably be a bit higher, but we'll take it. After an 11-5 beatdown last night, the Dodgers will be looking to repeat that success at the dish. That shouldn't be too difficult with Ryan Feltner on the mound for Colorado. The Rockies' right-hander has posted an 8.37 ERA and 1.99 WHIP over his last five starts.

The Dodgers' bats are going to be too much for this ice-cold Rockies offense, and there's no reason to force the dog here.

Odds are correct at the time of publishing and are subject to change.
Not intended for use in MA.
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Colby Marchio
Betting Analyst

Colby Marchio is a two-time DePaul alum and former Division 1 (club) baseball player who has been sports betting since 2019. Since graduating in 2021, he has worked throughout the media circuit, hosting and appearing on various television and radio shows while making countless guest appearances discussing Major League Baseball, college basketball, college football, and the National Football League.

A self-proclaimed numbers nerd, Colby may enjoy digging through the data even more than winning itself. That passion is why his two favorite sports to cover are college basketball and Major League Baseball. 

As for his favorite sportsbook, it is whichever one has the best price, or whichever one is not taxing him as an Illinois resident. 

You can find all of his plays and more @ColbyMBets on Twitter/X.

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