Best MLB prop bets May 31: Fade Merrill, look for Grisham to mash in plus matchup

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, featuring a prediction on Trent Grisham.

MLB prop bets

Best Bet: Grisham over 1.5 total bases (+132) 

Grisham has earned his promotion within the New York Yankees’ batting order, and now he has the best lineup protection imaginable.

On a nightly basis, the left-hitting centerfielder bats just ahead of all-world slugger Aaron Judge.

When there’s an MVP favourite in the on-deck circle, pitchers tend to give the guy at the plate something to hit. I think Dodgers right-hander Landon Knack will do that anyway for Grisham, given that he’s only allowed four walks over his past four outings.

Knack is off to a rough start through seven appearances (29.1 innings):

  • 30 hits allowed
  • 5.22 ERA
  • .479 SLG

To make matters worse, his xERA (5.35) and xSLG (.513) are both higher than his already inflated numbers.

Grisham has been tagging right-handed pitchers this year (.667 SLG in 99 at-bats) and looks like a good fit to keep that up against Knack.

More than 75.0% of Knack’s pitches to lefties this season have been four-seam fastballs or changeups, per Baseball Savant.

Against four-seamers and changeups thrown by righties, Grisham has an exceptional .321/.429/.792 slash line in 53 at-bats.

Key stat: Grisham has 79 total bases across 38 starts this season (2.08 bases per game).

Embed: #114317

Best MLB picks

Witt under 1.5 bases (-136): 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.

Merrill under 0.5 runs (-141): 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.

MLB prop picks made at 11:40 a.m. ET on 05/31/2025.

Website | + posts

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.