On the other side, the St. Louis Cardinals start Kyle Leahy, who carries a 3.07 ERA from 2025, but that number comes entirely from short relief work. His last three outings before tonight were 3.0 innings, 1.0 inning, and 1.0 inning. Now St. Louis is asking a burst reliever to navigate a full starting workload on opening night in tonight's MLB action, against a Mets offense averaging 6.0 runs per game through three contests. That structural mismatch is the engine driving the case for the Under and for New York's lineup to eventually break through. Our model projects 8.1 total runs versus a 9.0 market line, the sharpest single-game discrepancy in today's slate.

The batter-versus-pitcher data against Holmes makes the Cardinals' offensive ceiling even harder to see. Nolan Gorman is 0-for-6 with a 0.000 OPS in six career plate appearances against Holmes. Jordan Walker, who is slashing .400/.500/.900 to open 2026 and looks like one of St. Louis's most dangerous bats right now, is 0-for-4 against Holmes with a 0.000 OPS across two seasons of contact. When your two hottest hitters have a combined zero hits and zero extra bases against the opposing starter, your run-scoring ceiling shrinks considerably. Busch Stadium's 0.95 HR factor makes it even harder to manufacture offense through the long ball.

The contrarian case for St. Louis deserves a sentence. Masyn Winn is 2-for-3 with a 1.334 OPS against Holmes in 2025 plate appearances, and Holmes's walk rate has been drifting upward (3.59 BB/9 in 2025 versus 3.24 the year before). Season opener command variance is real, and the Cardinals are 2-0 against right-handed pitching so far this year. At +125, there is marginal underdog value if Holmes is hittable early. But the Cardinals carry a 10.38 bullpen ERA after three games, meaning any deficit they fall into is almost impossible to dig out of with that relief corps. The structure here points in one direction.

• Holmes has held this Cardinals lineup to 1 and 3 earned runs in two recent six-inning starts. His sinker-heavy approach is tailored for Busch Stadium's spacious outfield and suppressed HR environment, making this one of the cleaner pitcher-park alignments on the slate.
• Leahy's 3.07 ERA was built exclusively in short relief stints. His last three appearances totaled just 5.0 innings. Projecting 6-plus innings from him against a Mets lineup that has scored 18 runs in three games is asking something he has not proven he can deliver.
• Gorman (0-for-6, 0.000 OPS vs Holmes) and Walker (0-for-4, 0.000 OPS vs Holmes) are the Cardinals' two most dangerous hitters by early-season numbers, and both are historically dominated by this specific pitcher. That caps St. Louis's ceiling in the middle of the lineup.
• The bullpen gap is stark: NYM carries a 2.45 ERA from relievers, STL sits at 10.38. If Leahy exits early and the Cardinals fall behind, their pen has almost no capacity to hold the game. That asymmetry reinforces both the Mets' win probability and the under projection.
• Winn (1.334 OPS vs Holmes in 2025) is the one Cardinals hitter with proven success against this pitcher and represents the primary threat to Holmes's game plan. If Winn gets on base early and the lineup clusters hits, that is how STL manufactures a crooked number.
• Both starters are making their first regular-season appearances of 2026. First-game command variance is real, particularly for Holmes, whose walk rate has been trending up. A control hiccup in the first inning could shift the early-innings picture quickly.

The best angle is the Under 8.5 at -106. A 0.9-run gap between our 8.1 projection and the 9.0 market line is the sharpest discrepancy on the slate, and the individual matchup data supports it from multiple angles: Holmes's sinker-ball fit with Busch Stadium's suppressed HR environment, the Gorman and Walker BvP futility, and Leahy's untested stamina as a starter. The Cardinals +1.5 is the sensible complement. A close, pitcher-controlled game is far more likely than a Mets blowout, and the cushion covers you if St. Louis stays competitive through six or seven innings.

The caveat is real: both pitchers are making season debuts, and first-game command is legitimately uncertain. Holmes walked 66 batters in 2025, and if his walk rate spikes in a cold, rusty start, the Cardinals can manufacture runs without needing hits from their two Holmes-dominated bats. Winn has a 1.334 OPS against Holmes from 2025 and represents a genuine threat. This is not a lock. But when the model, the park, the BvP data, and the bullpen mismatch all point the same direction, the structure is hard to ignore. Projected final: New York 5, St. Louis 3.