Toronto Blue Jays vs Seattle Mariners Prediction – 5/9/2025

On May 9, 2025, the Seattle Mariners will host the Toronto Blue Jays at T-Mobile Park in what marks the first game of their series. The Mariners enter this matchup with a strong 22-14 record, showcasing a solid start to the season. Meanwhile, the Blue Jays, at 17-20, have struggled and sit lower in the standings, reflecting a below-average season thus far.

Luis Castillo is projected to take the mound for the Mariners, fresh off an impressive season where he boasts a 3.29 ERA. While his 4.59 xFIP suggests he might have been a tad fortunate, his ERA still places him among the upper echelon of pitchers. Despite being a low-strikeout pitcher with an 18.2% strikeout rate, he faces a Blue Jays lineup that is also low in strikeouts, which could play in Toronto's favor. However, Castillo has the advantage of a low home run rate, particularly since the Blue Jays have only hit 26 home runs this season, ranking 30th in MLB.

On the other side, Kevin Gausman will represent the Blue Jays. He has a respectable 3.83 ERA but has struggled with a 2-3 record this season. Gausman's tendency to allow fly balls—43% so far—presents a precarious match-up against a Mariners offense that ranks 4th in MLB in home runs, thanks to their impressive 51 homers.

Seattle's offense leads the league in several categories, including 4th in runs scored and 3rd in stolen bases, while Toronto's offense appears lackluster, sitting 24th overall. Given this comparison, the projections suggest that the Mariners hold a notable advantage, especially considering their potent lineup against Gausman's fly-ball tendencies. The Game Total is set at a low 7.5 runs, further hinting at a potential pitching duel. With Seattle being the betting favorite at -140, this matchup promises an exciting start to the series.

Quick Takes Toronto Blue Jays:

In his previous start, Kevin Gausman was firing on all cylinders and gave up 2 ER.

• A pitcher who was strong in his last outing may be sharp once again in his next outing.

When it comes to his home runs, Alejandro Kirk has suffered from bad luck since the start of last season. His 8.3 HR per 600 plate appearances rate has been significantly deflated relative to the leading projection system (THE BAT X)'s version of Statcast-based Expected HR/600 at 16.3.

• xHR uses highly advanced Statcast data to measure a player's home run ability more accurately than actual home runs can.

The Toronto Blue Jays bullpen profiles as the 6th-best in the game, per the leading projection system (THE BAT).

• Most bettors only consider the starting pitcher, but a strong bullpen sneakily creates a tougher matchup for the opposing offense and suppresses a game's runs.

Quick Takes Seattle Mariners:

Compared to the average pitcher, Luis Castillo has been given a longer leash than the typical pitcher this year, tallying an extra 4.2 adjusted pitches each start.

• Pitchers with a longer leash are more likely to go deeper into games and record more outs.

J.P. Crawford is penciled in 1st in the batting order today, which would be an upgrade from his 80% rate of hitting in the bottom-half of the lineup this season.

• The higher in the order a player bats, the more plate appearances he will get and the more opportunities he will get to hit the Over for every market. A player who hits higher in the order than he normally does may provide extra value opportunity since the market may be based on him hitting lower.

Cal Raleigh pulls many of his flyballs (42.4% — 100th percentile) and will have a big advantage hitting them towards the league's 4th-shallowest RF fences today.

• This player's skill set matches up particularly well with the park he's in today, which may lead to better-than-usual performance.

Game Trends

• The Seattle Mariners have hit the Game Total Over in 14 of their last 18 games (+9.55 Units / 49% ROI)
• The Toronto Blue Jays have hit the 1st Five Innings (F5) Team Total Under in 13 of their last 17 away games (+9.45 Units / 48% ROI)
• Rowdy Tellez has hit the Runs Over in 6 of his last 10 games (+6.40 Units / 64% ROI)

Toronto Blue Jays vs Seattle Mariners Prediction

Predicted Final Score: Toronto Blue Jays 3.99, Seattle Mariners 3.96

• Date: May 9, 2025
• Venue: T-Mobile Park
• Starting Pitchers:
  • Kevin Gausman - Blue Jays
  • Luis Castillo - Mariners

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