Ashcraft's dominance suggests one outcome — May's .377 xwOBA against his sinker points toward the opposite scoring environment entirely.
Pittsburgh Pirates vs St. Louis Cardinals MLB Betting Preview
After dominating the Cardinals 7-0 yesterday, the Pittsburgh Pirates send Braxton Ashcraft to the mound against Dustin May in what shapes up as a significant pitching mismatch. The Pirates opened as -134 moneyline favorites, but that price pushes beyond comfortable juice territory for a standalone play. The total sits at 7.5, and with Ashcraft's solid peripherals facing May's struggles, this game projects to exceed that number by a meaningful margin.
I looked at the Pirates moneyline here, but -134 is too steep to chase when the underlying edge points toward run production rather than side selection. The pitching disparity that makes Pittsburgh attractive also suggests both offenses will find opportunities against the opposing starter.
Game Information & Betting Odds
- Matchup: Pittsburgh Pirates @ St. Louis Cardinals
- Date: Thursday, May 21, 2026
- Time: 1:15 PM ET
- Location: Busch Stadium
- TV: ESPN Unlimited, MLB.TV, Cardinals.TV
- Moneyline: Pittsburgh Pirates -134 / St. Louis Cardinals +114
- Run Line: St. Louis Cardinals +1.5 (-156) / Pittsburgh Pirates -1.5 (+130)
- Total: 7.5 (Over -122 / Under +100)
- Starters: Braxton Ashcraft (2-2, 3.09) vs Dustin May (3-4, 4.81)
- Records: Pittsburgh Pirates 25-24 / St. Louis Cardinals 28-20
The Pitching Matchup
The gap between these starters is substantial. Ashcraft brings a 3.09 ERA and 1.05 WHIP compared to May's 4.81 ERA and 1.42 WHIP. From an efficiency standpoint on the mound, Ashcraft's superior command shows in his 56 strikeouts against just 14 walks over 55.1 innings. May's 35 strikeouts and 15 walks in 48.2 innings reflect the control issues that have plagued him this season.
Ashcraft's arsenal centers on a 96.8 mph four-seam fastball at 29.6% usage that holds hitters to a .315 xwOBA. His curveball at 85.0 mph generates a 39.5% whiff rate with a .218 xwOBA against – that's his put-away pitch. The Cardinals' lineup includes several right-handed hitters who struggle against breaking balls, particularly Nolan Gorman (.407 xwOBA but 33.2% whiff rate) and Thomas Saggese (28.3% whiff rate).
May's problems show up in his Statcast metrics. His sinker, thrown 18.8% of the time at 96.6 mph, gets hammered for a .377 xwOBA. The changeup has been a disaster – .412 xwOBA allowed with zero whiffs this season. That's the problem when you're facing a Pirates lineup that includes Brandon Lowe (.452 xwOBA, 7.0% barrel rate) and Oneil Cruz (.506 xwOBA, 9.6% barrel rate against right-handed pitching).
The concerning part for May is his negative -0.25 WAR compared to Ashcraft's positive 1.02 WAR. That differential suggests the quality gap extends beyond surface numbers. The Cardinals have scored just 4.62 runs per game this season, and facing Ashcraft's 96.8 mph fastball paired with that devastating curveball won't make run production easier.
But here's the problem with focusing solely on the pitching edge – May's struggles create opportunities for Pittsburgh's offense, which just exploded for seven runs yesterday. Spencer Horwitz homered in that game and carries a .293 xwOBA with excellent contact quality. The risk is that even with Ashcraft's dominance, May's inability to miss bats consistently keeps this total moving upward.
Prediction
This projects as a game where the superior starter controls his half while the inferior starter allows enough traffic to push the total over. Ashcraft should handle the Cardinals' lineup effectively, but May's .377 xwOBA against his sinker and .412 xwOBA against his changeup suggest the Pirates will generate scoring chances. The pick is Over 7.5 (-122), meaning the combined score must go over 7.5.
The concern is that over totals depend on the scoring environment cooperating throughout nine innings. Bullpen variance can flip late-game dynamics quickly. That said, what works for this bet is May's documented inability to miss bats consistently, combined with a Pirates offense that just found its rhythm yesterday. I'd lean over 7.5 as a small play – the moneyline at -134 is too pricey to chase.
Projected Final Score: Pittsburgh Pirates 5, St. Louis Cardinals 4