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Best MLB player prop picks for today, 4/21: Mariners score off Cal Quantrill

Best MLB player prop picks for today, 4/21: Mariners score off Cal Quantrill

Javan Shouey
Javan ShoueyAuthor
UpdatedAug 21, 2026
Reading time2 min

Patrick Sandoval was roughed up by the Cincinnati Reds yesterday evening, giving us any easy winner on his under 15.5 outs prop. Today we are shifting gears and attacking a different market. Let’s head to Colorado and see why I am looking to bet on the Seattle Mariners offense early in this matchup against Cal Quantrill.

Seattle Mariners first 5 innings team total Over 2.5 (-130)

Odds available at DraftKings Sportsbook at time of publishing. Playable to -140. 1u.

It is no secret that I have enjoyed betting against Cal Quantrill over the years, as the 29-year-old right-hander struggles in areas that prevent runs. A shift from pitching in Cleveland to Colorado is not exactly a cure for his weaknesses, and pitching at elevation in a huge park is likely to lead to troubles this season. Quantrill’s first outing at Coors Field this season resulted in just 3 earned runs allowed to the Diamondbacks, but he was fortunate to not allow more given 8 hits and 2 home runs surrendered. Arizona did cover this 2.5 team total within the first 5 innings, actually doing so within the first 2 frames. Quantrill held the Phillies in check during his last start but has allowed 3 or more runs within the first 5 innings in each of his first 3 starts this year.

While there is solid reasoning for backing any offense against Quantrill, I am intrigued by this matchup for the Mariners. Seattle got rid of numerous high-strikeout rate bats from last season’s lineup but is still displaying poor plate discipline this season — holding it back from unlocking its full potential. I was a fan of the offseason depth the Mariners added to the lineup, and despite their struggles with making contact they still have an above average 101 wRC+ against right-handed pitching so far. A cure for poor contact rates is a matchup against Quantrill, who ranks just 5th percentile in whiff rate so far this season. Not only does Quantrill fail to miss bats, but the quality of contact that he allows is also very poor — ranking 37th percentile in both average exit velocity and barrel rate. Seattle’s lineup does possess quite a bit of raw power from multiple sources in the order and should be able to get to him early. With Quantrill having an outs recorded line of 15.5 and an earned runs prop of 3.5, getting 2.5 for the first 5 innings team total at playable juice is my preferred angle — especially considering unearned runs count for us.

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