Pirates vs. Cardinals Prediction, Odds, Probable Pitchers, Prop Bets for Thursday, May 21

The Pittsburgh Pirates and St. Louis Cardinals have split their first two games of their series this week, and Pittsburgh is actually set as a road favorite on Thursday afternoon.

The Pirates have youngster Braxton Ashcraft (3.09 ERA) on the mound against St. Louis’ Dustin May (4.81 ERA) in this series finale, as both teams battle for position in the best division in MLB (so far) in the 2026 campaign.

Pittsburgh is in last place in the NL Central, but it’s just five games out of the top spot. Meanwhile, the Cardinals are second in the division, 1.5 games behind the Milwaukee Brewers.

So, how should we bet on this series finale?

I’m eyeing a player prop and a side on Thursday, as Pittsburgh looks to stay over .500.

Pirates vs. Cardinals Odds, Run Line and Total

Odds via DraftKings Sportsbook

Run Line

Pirates -1.5 (+134)
Cardinals +.1.5 (-157)

Moneyline

Pirates: -132
Cardinals: +109

Total

7.5 (Over -104/Under -119)

Pirates vs. Cardinals Probable Pitchers

Pittsburgh: Braxton Ashcraft (2-2, 3.09 ERA)
St. Louis: Dustin May (3-4, 4.81 ERA)

Pirates vs. Cardinals How to Watch

Date: Thursday, May 21
Time: 1:15 p.m. EST
Venue: Busch Stadium
How to Watch (TV): Cardinals.TV/ESPN Unlimited
Pirates record: 25-24
Cardinals record: 28-20

Pirates vs. Cardinals Best MLB Prop Bets

Pirates Best MLB Prop Bet

Oneil Cruz to Hit a Home Run (+509)

Earlier today, I shared in SI Betting’s best home run picks – Daily Dinger – why Cruz is a great prop target:

Pittsburgh Pirates star Oneil Cruz has only three at-bats against St. Louis Cardinals righty Dustin May in his career, but he took him yards in one of those matchups.

So, I’m taking a shot on Cruz at +509 in Thursday’s afternoon showdown.

Cruz is hitting .286 over the last two weeks with one home run, but he’s homered six times against right-handed pitching and has a .784 OPS in the 2026 campaign.

Those numbers aren’t great, but Cruz has some serious power and is hitting .464 on batted balls in play over the last two weeks.

May has only given up four home runs in nine appearances this season, but he’s also posted a 4.81 ERA. I think Cruz is worth a bet at this price in this series finale.

Pirates vs. Cardinals Prediction and Pick

There’s no doubt that Ashcraft is the better starter in this matchup, as he ranks in the 85th percentile in expected ERA and the 82nd percentile in expected batting average against.

Meanwhile, May is in just the 36th and 20th percentile in those two categories, a sign that his 4.81 ERA is right where you’d expect it to be this season.

The Cardinals are 5-4 when May takes the mound this season, but he’s allowed at least three runs in five of those outings. The opposite can be said for Ashcraft, and he’s given up two or fewer earned runs in seven of nine starts.

Pittsburgh has been pretty solid on the road (12-11), and I’d much rather bet on Ashcraft in this matchup than May. The advanced numbers for May are shaky, and he’s struggled to induce a lot of swings and misses, ranking in the seventh percentile in MLB in whiff percentage and the second percentile in hard-hit percentage this season.

Pick: Pirates Moneyline (-132 at DraftKings)

Odds refresh periodically and are subject to change.

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