Keller's 1.08 WHIP creates a clear pitching edge against Liberatore's power vulnerability — but Pittsburgh just scored zero runs in consecutive games while the market prices this as a coin flip.
Pittsburgh Pirates vs St. Louis Cardinals MLB Betting Preview
The market has this game essentially pick'em with Pittsburgh Pirates at -108 and St. Louis Cardinals at -108, but the pitching matchup suggests there's value on the visiting Pirates. Mitch Keller brings a 1.0822 WHIP and superior command to face Matthew Liberatore, who's struggled with a 1.5106 WHIP and concerning power vulnerability — 9 home runs allowed in just 47 innings pitched.
Here's my concern though: Pittsburgh just got shut out in back-to-back games at home against quality Philadelphia pitching, managing just nine total hits across those two losses. The Pirates offense has looked completely lost lately, scoring zero runs in their last two games while striking out 17 times. Meanwhile, St. Louis has been solid at Busch Stadium and just took two of three from Kansas City in their last series. That's real friction against this Pirates lean.
But the season-long numbers still favor Pittsburgh's offensive edge (.720 OPS vs .709 OPS) and significantly better pitching staff (3.88 ERA vs 4.12 ERA). The total sits at 8 runs, which feels about right given both teams' recent offensive struggles.
Game Information & Betting Odds
- Matchup: Pittsburgh Pirates @ St. Louis Cardinals
- Date: Tuesday, May 19, 2026
- Time: 7:45 PM ET
- Location: Busch Stadium
- TV: MLB.TV, Cardinals.TV
- Moneyline: Pittsburgh Pirates -108 / St. Louis Cardinals -108
- Run Line: St. Louis Cardinals +1.5 (-188) / Pittsburgh Pirates -1.5 (+155
- Over/Under: 8 (O -115 / U -105)
- Probable Starters: Mitch Keller (4-2, 3.59) vs Matthew Liberatore (2-2, 4.40)
- Records: Pittsburgh Pirates 24-23 / St. Louis Cardinals 27-19
The Pitching Matchup
This is where the betting angle gets interesting. Keller's 34.4% four-seam fastball sits at 93.4 mph and holds hitters to a .376 xwOBA, while his 18.8% sweeper generates a 24.0% whiff rate with just .260 xwOBA against. The Pirates right-hander has allowed only 3 home runs in 52.2 innings — a stark contrast to Liberatore's power problems.
Liberatore's 33.2% four-seam fastball at 94.3 mph gets crushed to a .455 xwOBA, and that's the root of his issues. His slider generates solid whiffs at 37.7%, but when hitters make contact with his fastball, they're doing significant damage. Nine home runs in 47 innings pitched tells the story of a pitcher who can't command his primary offering in the strike zone.
The Cardinals lineup does have some thunder — Jordan Walker's .501 xwOBA with 8.7% barrel rate makes him the most dangerous hitter in this matchup, and Alec Burleson's .426 xwOBA shows consistent quality of contact. But here's the problem: Keller's track record suggests he can navigate this lineup better than Liberatore can handle Pittsburgh's more disciplined approach.
Oneil Cruz's .508 xwOBA and 9.7% barrel rate creates a mismatch against Liberatore's fastball-heavy approach, while Brandon Lowe's .447 xwOBA gives the Pirates another quality bat early in the order. The BvP data shows Bryan Reynolds is 4-for-12 lifetime against Liberatore with a home run, which adds another layer of concern for the Cardinals starter.
From an efficiency standpoint on the mound, the Pirates hold every meaningful advantage. Keller's 1.0822 WHIP versus Liberatore's 1.5106 WHIP reflects better command and fewer free passes. The concern is that Pittsburgh's offense has looked completely anemic recently — getting shut out by Zack Wheeler and Cristopher Sánchez in consecutive games, managing just four and five hits respectively.
Prediction
I seriously considered Pittsburgh Pirates -1.5 at +155, but there are too many red flags. First, Keller's road splits could be concerning — I don't have his specific road numbers, but any pitcher can struggle away from home. Second, the Cardinals just showed life at home against Kansas City, winning two of three while the Pirates are coming off that brutal sweep by Philadelphia. Third, laying runs with a team that just scored zero runs in consecutive games feels dangerous, especially when their opponent has legitimate pop in Walker and Burleson.
The pitching matchup still tilts this toward Pittsburgh, with Keller's superior command profile creating enough of an edge to overcome the Cardinals' home field advantage and better record. At essentially pick'em pricing, I'm taking the Pirates moneyline despite my concerns about their recent offensive struggles.
The key is that Pittsburgh's season-long metrics suggest they're due for regression to the mean against a volatile starter like Liberatore. His .455 xwOBA allowed on his primary fastball is unsustainable, and the Pirates have enough quality contact hitters to exploit that weakness.
Final Score Prediction: Pittsburgh Pirates 5, St. Louis Cardinals 4
Best Bet: Pittsburgh Pirates Moneyline (-108)