Painting Corners: Best MLB Prop Bets Today (Luis Gil, Luis Castillo Should Thrive on the Mound)

Breaking down the best prop bets to place for the Major League Baseball action on Thursday, June 20.
Seattle Mariners starting pitcher Luis Castillo.
Seattle Mariners starting pitcher Luis Castillo. / Stephen Brashear-USA TODAY Sports

It’s a travel day in Major League Baseball, which means there are just nine games – instead of 15 – to bet on. 

There are a couple of prop bets I’m eyeing on tonight’s slate, with two star right-handers looking to build on their strong starts to the 2024 season. 

The first prop comes in the New York Yankees-Baltimore Orioles matchup, which went to extra innings on Wednesday night with the O’s pulling out a win. Starter Luis Gil gets the ball for New York, and oddsmakers may be undervaluing him after a couple of outings where he showcased some command issues (eight walks over the last three games). 

Plus, there’s a play for Seattle Mariners ace Luis Castillo that I love tonight. Let’s break down these bets to send ourselves into the end of the week on a high note. 

Best MLB Prop Bets for Thursday, June 20

  • Luis Gil UNDER 2.5 Earned Runs Allowed (-165)
  • Luis Castillo OVER 4.5 Strikeouts (+115)

Odds via DraftKings Sportsbook.

Luis Gil UNDER 2.5 Earned Runs Allowed (-165)

Gil has been one of the best pitchers in baseball this season, posting a 2.03 ERA in 14 starts (the Yankees are 12-2 in those games). 

While the rookie did allow three runs in a win over the Los Angeles Dodgers on June 9, Gil has still given up two or fewer runs in 11 of his 14 starts and eight of his nine starts since May 1. 

Since May 1, he’s compiled a 1.14 ERA while holding his opponents to a .128 batting average. That bodes well for him against the Orioles, who did not score and picked up just two hits against Gil across 6.1 innings of work earlier this season. 

We do have to lay some juice with this prop, but Gil is hitting the UNDER on his earned runs at an insanely high rate in 2024. He’s worth taking on Thursday night.

Luis Castillo OVER 4.5 Strikeouts (+115)

Castillo doesn’t have the easiest matchup on Thursday against the Cleveland Guardians, but he could be undervalued in his strikeout prop. 

The Guardians average just 7.25 strikeouts per game this season, but Castillo needs just five to clear this prop, something he’s done in 12 of his 15 starts in 2024. 

There are a couple of advanced stats that I love for the Mariners ace here, especially his chase percentage. Castillo is in the 85th percentile in chase percentage, 69th in strikeout percentage and 64th in whiff percentage. 

The other reason I love this prop is out of the 12 games that Castillo finished with five or more punch outs this season, 11 of them have come with him picking up six or more. So, he doesn’t even have to put up one of his best games to get past this prop. 

At plus money, this is an easy bet for one of baseball’s top pitchers.

Odds refresh periodically and are subject to change.

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Peter Dewey


Peter is a senior editor for Sports Illustrated Betting. He has worked as a writer and editor for BetSided, NBC Sports, the Connecticut Sun and the Meriden Record-Journal covering the NBA, WNBA, NFL, MLB, and more. A New York City resident, he is a hoops fanatic with a soft spot for his New York Knicks.