Find the Best Player Prop Bets for Mariners vs Royals – 9/16/25

Seattle Mariners

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Kansas City Royals

As the Kansas City Royals prepare to face the Seattle Mariners on September 16, 2025, the matchup presents an interesting dynamic with both teams coming off impressive wins. The Royals recently defeated the Mariners 10-3, showcasing their offensive potential, while the Mariners secured an 11-2 victory in their last outing against another opponent. This series opener holds significance as the Royals look to build on their recent momentum, despite being outperformed in the standings.

The Royals, currently sitting at 75-75, are having an average season, and their offense ranks 25th in MLB, which is concerning heading into this game. They will rely on Michael Wacha, who has had an up-and-down year with a 9-11 record and a solid ERA of 3.45. However, his xFIP of 4.51 suggests he might have enjoyed a bit of luck on the mound this season. Wacha’s tendency to allow 5.1 hits and 1.5 walks per game could be problematic against a Mariners lineup that ranks 12th in offensive production and leads MLB in home runs.

On the other side, Seattle’s Logan Gilbert, who boasts an impressive 15th ranking among MLB’s starting pitchers, is projected to have a better outing. With a 4-6 record and a 3.54 ERA, the projections indicate Gilbert has been unlucky this season, as evidenced by his xFIP of 2.73. Given that the Royals have the lowest strikeout rate in MLB, Gilbert could capitalize on this matchup effectively.

As the game total sits at an average 8.5 runs, the Mariners are favored with a moneyline of -140. The Royals, though underdogs, have shown flashes of offensive power recently and will aim to exploit any weaknesses in Gilbert’s performance. This game not only highlights the contrasting fortunes of both teams this season but also sets the stage for an intriguing battle between a solid pitcher and a lineup that needs to prove its worth.

Seattle Mariners Insights

• Logan Gilbert – Over/Under 17.5 Pitching Outs (-140/+110)
  The leading projection system (THE BAT X) projects that Logan Gilbert will rack up an average of 16.7 outs in today’s outing.
  Explain: THE BAT X is a highly sophisticated projection system that accounts for a multitude of factors like ballpark, weather, umpire, defense, and more.
• Julio Rodriguez – Over/Under 1.5 Total Bases (-120/-110)
  Julio Rodriguez has seen a substantial improvement in his exit velocity in recent games; just compare his 94.7-mph average in the last 14 days to his seasonal 91.6-mph mark.
  Explain: Hitting the ball hard increases the chances of either a home run or the ball landing in fair territory for a hit before a fielder can get to it.
• Seattle Mariners bats as a unit place 7th- in Major League Baseball for power this year when judging by their 9.5% Barrel%.
  Explain: Barrel% measures how often a player hits the ball at the optimal exit velocity and launch angle and is a terrific measure of underlying power.

Kansas City Royals Insights

• Michael Wacha – Over/Under 3.5 Strikeouts (-155/+120)
  Michael Wacha has used his change-up 6.9% less often this year (25.4%) than he did last season (32.3%).
  Explain: Because change-ups are one of the most effective pitches to use, a pitcher who alters his pitch mix to use them less often may see less success as a result, particularly if he uses his fastball more instead.
• Jac Caglianone – Over/Under 0.5 Total Bases (-150/+120)
  Based on Statcast data, the leading projection system (THE BAT X)’s version of Expected wOBA (.338) implies that Jac Caglianone has experienced some negative variance this year with his .229 actual wOBA.
  Explain: xwOBA uses highly advanced Statcast data to measure a player’s overall hitting ability more accurately than actual wOBA can.
• Jac Caglianone – Over/Under 0.5 Total Bases (-150/+120)
  Jac Caglianone hits many of his flyballs to center field (39.7% — 95th percentile) and has the misfortune of hitting them in the direction of the game’s 4th-deepest CF fences in today’s matchup.
  Explain: This player’s skill set does not match up particularly well with the park he’s in today, which may lead to worse-than-usual performance.

Betting Trends

• Kansas City Royals – Over/Under 3.5 Team Total (-125/-105)
  The Kansas City Royals have hit the Team Total Under in 84 of their last 137 games (+26.35 Units / 16% ROI)
• Over/Under 8.5 Game Total (-110/-110)
  The Seattle Mariners have hit the Game Total Over in 73 of their last 130 games (+15.00 Units / 11% ROI)
• Julio Rodriguez – Over/Under 2.5 Hits Runs and RBIs (+110/-145)
  Julio Rodriguez has hit the Hits Runs and RBIs Over in 17 of his last 25 away games (+8.95 Units / 30% ROI)