August 21, 2025

Game Preview

Written by: Michael Rivera

Michael is a data-driven baseball enthusiast who specializes in pitch analytics and betting trends.

Cardinals vs Rays: Betting Preview & Props (Aug 21)

Last updated: August 21, 2025

Game Time: 8/21, 07:35PM

Matchup Setup

Tonight, the St. Louis Cardinals take on the Tampa Bay Rays in what promises to be a compelling matchup. With DraftKings listing the Cardinals as a -123 favorite and the Rays as a +101 underdog, 51% of the betting money is favoring the Rays. Bettors should focus on the starting pitchers and lineup matchups to gain an edge.

Starting Pitching Analysis

Pitching Matchup: Sonny Gray vs Joe Boyle

Sonny Gray (STL):

Gray boasts a versatile pitch arsenal: Four-Seam Fastball (23% usage, 91.7 mph), Sweeper (20% usage, 85.0 mph), Curveball (17% usage, 80.1 mph), Sinker (17% usage, 92.2 mph), Cutter (12% usage, 88.0 mph), Changeup (9% usage, 86.2 mph), and Slider (2% usage, 84.4 mph). As a pitch-mix artist, Gray utilizes a wide array of pitches to keep hitters off-balance. The Rays lineup averages .278 this season but projects a .263 xBA against Gray's diverse offerings.

Joe Boyle (TB):

Boyle is a velocity-heavy pitcher, relying primarily on his Four-Seam Fastball (55% usage, 98.6 mph), complemented by a Slider (31% usage, 91.2 mph) and a Splitter (14% usage, 93.2 mph). The Cardinals lineup, with a season average of .258, projects a decrease to a .235 xBA against Boyle's high-speed arsenal.

Lineup Matchups

Lineup Matchups & Batting Edges

For Cardinals vs Joe Boyle: The Cardinals lineup averages .258 this season but projects to .235 against Boyle's heat-heavy arsenal.

Biggest Decrease:

Iván Herrera: Season BA .285 → xBA vs Boyle .203 (-82 points), Season K% 21.1% → Arsenal K% 23.4% (+2.3%)

For Rays vs Sonny Gray: The Rays lineup averages .278 this season and projects a .263 xBA against Gray's mix.

Biggest Decrease:

Ha-Seong Kim: Season BA .304 → xBA vs Gray .258 (-46 points), Season K% 28.8% → Arsenal K% 28.0% (-0.8%)

K-Risk Analysis

Strikeout Risks & Rewards

The Cardinals' projected K-rate is 25.2% vs Boyle — up 3.8% from their 21.3% season average.
The Rays' projected K-rate is 21.3% vs Gray — up 0.4% from their 20.9% season average.

Umpire Influence

Behind the Plate: Umpire assignment has not been announced, which makes prop volatility a concern.

What to Bet On

Checking all individual batters for prop opportunities yielded no batter meeting both the criteria of xBA > 0.300 and a boost > +20 points.

Strikeout prop opportunities:

⚡ K Prop Alert: Joe Boyle strikeout OVER - Cardinals' K-rate jumps to 25.2% vs this arsenal!

No significant statistical edges meet our betting threshold in other categories.

🔑 Key Takeaways

Iván Herrera of the Cardinals sees a significant drop in expected batting average, making him a potential fade in prop markets.
Joe Boyle's high-velocity arsenal could exploit the Cardinals' elevated strikeout rate, presenting a strikeout prop opportunity.
Umpire volatility due to TBA assignment could affect betting outcomes, particularly in prop markets.
Overall, focus on Boyle’s strikeout potential as the key betting angle given the matchup dynamics.

🧠 FAQs

Q: Who is the best betting prop for the Cardinals vs Rays game? A: Joe Boyle's strikeout OVER is a strong consideration as the Cardinals' K-rate increases significantly against his arsenal.

Q: Is the umpire a pitcher-friendly umpire? A: Umpire assignment has not been announced, creating potential volatility in prop markets.

Q: What time is the Cardinals vs Rays game? A: 8/21, 07:35PM

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