Best MLB prop bets May 31: Fade Jackson Merrill in lefty-on-lefty matchup vs. Pirates

MLB prop bets

Two of MLB’s brightest young stars, Bobby Witt Jr. and Jackson Merrill, feature in my MLB prop bets for Saturday.

Today’s MLB props narrative: Merrill is a heart-of-the-order bat who hasn’t found his footing against lefty pitchers yet — and he’s facing a surging one tonight. Witt is also fade-worthy against arguably the best pitcher in the game, Tarik Skubal.

Check out my top MLB prop bets for May 31.

MLB prop bets

Best Bet: Merrill under 0.5 runs (-154) 

Batting order position matters a lot to me for run props, and I think Merrill’s spot in the heart of the order makes him fade-worthy a lot of the time.

  • Merrill has batted in the No. 4 or 5 spot in 29 of 30 games this season.
  • He’s gone under 0.5 runs in 12 of his past 15 games, posting a .242 OBP in that span.

Merrill will also be subjected to a lefty-on-lefty matchup tonight, which is far from ideal for him.

The centerfielder has a .277 OBP in his career vs. LHPs (compared to a .355 OBP vs. RHPs).

Pirates southpaw Bailey Falter has allowed just three earned runs in five starts this month, good for a 0.92 ERA. That includes 7.0 innings of two-hit ball against the Padres on May 3.

Key stat: Merrill has gone under 0.5 runs in 17 of 30 games (56.7%).

Best MLB picks

Witt under 1.5 bases (-118): With Skubal on the mound for the Detroit Tigers today, Witt and the rest of the Royals’ lineup are in an unenviable spot.

  • Skubal, the reigning AL Cy Young winner, leads the majors in FIP (1.97) and currently has a career-low 0.845 WHIP.
  • Witt is 4-for-27 (.148) against Skubal with zero extra-base hits and six strikeouts.

Skubal has the best changeup in the game, and it runs away from right-hitting players like Witt. The pitch has a 50.0% whiff rate and a .198 SLG in 88 plate appearances.

Witt has gone under 1.5 bases in seven of his past 12 games, posting a .184/.192/.327 slash line in that span.

MLB prop picks made at 2:00 p.m. ET on 05/31/2025.

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Jordan enjoys writing data-driven game previews and analysis articles — especially for MLB markets or NFL/NBA props. And as a proud Ohio University grad, he’ll always have a soft spot for college sports (especially if the Bobcats are involved). Previous stops include mlb.com, Sportsnet and The Athletic.