Best MLB Parlay for Opening Day 2025 (+666 Odds)

• Our high-value MLB Opening Day parlay offers +666 odds for Thursday, March 27th action
• This three-leg parlay features two underdog moneylines and a promising under bet
• Each selection is backed by detailed analysis and key statistical advantages

Baseball is back! The 2025 MLB season opens Thursday, March 27th with a perfect opportunity to cash a lucrative Opening Day parlay. We’ve constructed a three-leg combination offering tremendous +66 odds that could turn a $100 wager into over $600 in profit.

Our parlay targets value in two underdog moneylines and a promising over bet, taking advantage of early-season misconceptions about team strengths and pitching matchups. While casual bettors follow public sentiment, our analysis reveals key advantages that oddsmakers haven’t fully accounted for.

Below we break down each leg of our Opening Day parlay, highlighting the statistical edges and situational factors that make this combination worth backing as the new season begins:

MLB Opening Day Parlay (+666)

With Opening Day offering a full slate of games, we’ve identified three high-value plays that combine for a potential +666 payout. This parlay features two live underdogs with pitching advantages and matchup edges, plus a total that should stay under the number.

Let’s break down each selection and explain why these picks offer the perfect combination of value and probability for your Opening Day betting card. Check out our MLB odds for more betting lines.

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MLB Parlay Pick #1: Cubs ML

Kicking off our MLB parlay is a play on the Chicago Cubs moneyline in their matchup with the Arizona Diamondbacks. The public is loading up on the D-Backs in the MLB betting trends, but there is good reason to fade them in the season opener against

For starters, the Cubs have already played two regular-season games against the Dodgers in Tokyo, which could give them an edge in terms of being more prepared and in rhythm. The Diamondbacks, meanwhile, are playing their first game of the campaign on Thursday.

Chicago also has a nice pitching edge with Justin Steele on the mound. The 29-year-old typically performs well against Arizona, with 25 strikeouts and a 1.00 ERA over his last 18 innings pitched against them.

On the flip side, Chicago’s lefty-heavy lineup profiles well against Diamondbacks starter Zac Gallen.  In the previous season, the Cubs were in the top 10 for hard-hit rate against right-handed pitching.

There is also heightened urgency around the Cubs right now after starting the season 0-2 in Toxyo. The Cubs are favored to win the NL Central this season for a reason, and I think we see their current desperation help power them to an upset victory.

MLB Parlay Pick #2: Cardinals ML

Next up in our MLB parlay is the St. Louis Cardinals moneyline against the Minnesota Twins. While the Cardinals are slight underdogs at -105, there’s plenty of reason to back the home team in their Opening Day matchup at Busch Stadium.

The Cardinals send Sonny Gray to the mound for his first Opening Day start with St. Louis. Yes, Gray had a shaky spring, but the regular season is an entirely different animal. Gray is a proven veteran who tends to rise to the occasion in big moments, and Opening Day in St. Louis qualifies as exactly that.

Minnesota counters with Pablo López, who’s making his third straight Opening Day start but has his own question marks. López went 0-4 with an ugly 6.62 ERA in spring training. His recent form doesn’t inspire much confidence heading into a hostile environment.

The Cardinals’ offense features a balanced mix of veteran leadership and exciting young talent. Alec Burleson looks ready to break out in 2025, while Victor Scott II adds dynamic speed to their lineup. Don’t sleep on a Cardinals team that’s being overlooked after their “reset” offseason narrative.

Busch Stadium on Opening Day is one of baseball’s most electric environments – with the famous Clydesdales, thousands of red-clad fans, and numerous Cardinals legends in attendance. This home-field advantage is real and meaningful, especially for a team looking to make a statement to start their season.

At -105 odds, the Cardinals offer excellent value as the second leg of our Opening Day parlay. The bookmakers are realizing they have this wrong and are pushing the line toward St. Louis, and we’re jumping on it.

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MLB Parlay Pick #3: A’s vs Mariner Under 7 Runs

To complete our MLB parlay, I’m backing the Seattle Mariners and Oakland Athletics to stay under 7 runs in their Opening Day matchup at T-Mobile Park. This low total already signals a pitchers’ duel, but there’s value on the under for several key reasons.

The Mariners will send ace Logan Gilbert to the mound, who established himself as one of the American League’s elite arms last season. Gilbert was exceptional in 2024, finishing sixth in AL Cy Young voting while anchoring a rotation that dominated opposing lineups all year. The righty has proven to be particularly effective at pitcher-friendly T-Mobile Park.

On the other side, the Athletics counter with Luis Severino, who signed the largest contract in franchise history this offseason. While his time with the Yankees was inconsistent, Severino has plenty to prove with his new team and has the talent to match Gilbert in a low-scoring affair.

Seattle’s offense was their Achilles’ heel last season, and despite management’s promises, they failed to add the impact bats they desperately needed. Meanwhile, the Athletics begin a new chapter transitioning from Oakland to Sacramento, and Opening Day jitters could further hamper their offensive output.

With two quality starting pitchers, a pitcher-friendly ballpark, and offenses that project to be mediocre at best, this game has all the makings of a 3-2 or 2-1 type contest. Take the under to complete your parlay with confidence.