MLB Best Player Prop Bets for May 21

Getty The Washington Nationals kick their 2023 season off on March 30.

Player props provide an additional level of thrill to wagering on sports games. They offer valuable insights into a player’s ability to perform well in daily fantasy baseball or when placing bets on your preferred sportsbook.

Our AI-powered dfsPro model projects a number of individual performances worth keeping an eye on during today‘s games. Let’s dive into some of our favorite MLB player prop bets for May 21. All statistical research is from FanGraphs.

MLB Player Prop Bets

Lance Lynn Under 5.5 Hits Allowed (-145, DraftKings)

The Baltimore Orioles have struggled significantly against right-handed pitchers lately, ranking 28th in WRC+ and 29th in OBP over the past 15 days. Similar to Sonny Gray’s performance, many hitters see a drop in performance when facing righties. Gray, another right-handed pitcher for the St. Louis Cardinals, held the Orioles hitless for 5 innings yesterday before tiring in the 6th. Despite a tough outing against the Angels last time, Lynn has stayed under this line in 67% of his games this season. Expecting a bounce-back performance from Lance Lynn in this favorable matchup.

Casey Mize Under 2.5 ERA (-110, DraftKings)

This is a solid opportunity to back Casey Mize against a Kansas City Royals team struggling versus right-handed pitchers. He’s been under this line in 6 out of 8 starts (75%), even against the Royals on April 27, with his only rough outing against the New York Yankees.

The Royals have been notably weak against righties all season, especially evident in their 27th ranking in WRC+ over the past 15 days. With 6 out of 9 projected starters hitting .238 or worse against right-handers, there are ample chances for outs, though Bobby Witt Jr. and Salvador Perez pose challenges. Although wind conditions are a concern, the value at plus money makes this line too attractive to ignore.

Robert Gasser Over 15.5 Outs Recorded (-110, DraftKings)

Robert Gasser from the Milwaukee Brewers is set to pitch tonight, aiming to exceed his usual pitch count to around 90 pitches after a strong start to his big-league career. Despite his tendency for walks in the minors, the Miami Marlins, known for their low walk rate and aggressive hitting approach, might play into Gasser’s strengths. Additionally, the Marlins have struggled against left-handed pitchers recently, boasting just a 75 wRC+ since May 1st.

Lock of the Day

Patrick Corbin Over 5.5 Hits Allowed (-175, DraftKings)

Patrick Corbin has been consistently giving up 6 or more hits in 8 out of 9 starts this season. His expected batting average against (xBA) sits at a league-worst .322. Even if he’s expected to face just 20 batters (which is low), he’d still be projected to allow 6.44 hits. His metrics paint a grim picture too: bottom 5th percentile in hard-hit percentage, bottom 13th percentile in average exit velocity, and bottom 13th percentile in fastball velocity. 

On the flip side, the Minnesota Twins offense has been excelling against left-handed pitchers. Over the last 30 days, they own the MLB’s second-highest batting average against lefties at .296, including the fourth-best BABIP at .353. With Corbin’s tendency to allow balls in play, it’s a favorable matchup for Minnesota.

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