Seattle Mariners vs Chicago White Sox Prediction – 5/21/2025

The Chicago White Sox will host the Seattle Mariners on May 21, 2025, in what promises to be an intriguing matchup despite the White Sox’s struggles this season. The club enters this game with a dismal record of 15-34, currently sitting at the bottom of the standings. In contrast, the Mariners are enjoying a solid season at 27-20 and have the 10th best offense in MLB, with a potent lineup that features a high home run rate.

These two teams faced off just yesterday, with the White Sox managing a narrow 1-0 victory, a rare bright spot in what has been a challenging year. The White Sox will rely on Shane Smith, who has had a rollercoaster season. Though he holds a solid ERA of 2.05 and is ranked as the 99th best starting pitcher in MLB, projections suggest he may not sustain this performance. His xFIP stands at a concerning 4.05, indicating he has been somewhat fortunate so far.

On the other side, Logan Evans will take the mound for the Mariners. With a 2-1 record and an impressive ERA of 2.57, he has been solid in his limited starts. However, his xFIP of 4.69 suggests that he, too, might be living on borrowed time.

As the Mariners look to maintain their momentum, their lineup features players who are consistently delivering. They rank 6th in home runs and 8th in stolen bases, demonstrating a well-rounded offensive threat. Meanwhile, the White Sox not only rank 30th in overall offense but also in batting average, which puts additional pressure on Smith to deliver a strong outing.

With a game total set at 8.0 runs, expectations lean toward a challenging day for the White Sox’s lineup against Evans. The White Sox might be the underdogs with a moneyline of +135, but recent success and a solid showing from Smith could make for a competitive matchup.

Quick Takes Seattle Mariners:

The Seattle Mariners infield defense grades out as the worst out of all the teams today.

• Defense is an integral part of preventing (or, in this case, allowing) hits and runs.

Extreme groundball batters like Jorge Polanco generally hit better against extreme flyball pitchers like Shane Smith.

• This mostly has to do with the way the hitter's swing plane interacts with the pitch trajectory, and it can create boosted performance across all categories and hidden value few are considering.

Seattle Mariners bats collectively place 4th- in the majors for power this year when judging by their 10.7% Barrel%.

• 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.

Quick Takes Chicago White Sox:

Shane Smith is an extreme groundball pitcher (43.3% GB% per the leading projection system, THE BAT), which should make him somewhat immune to the dangers of pitching in Guaranteed Rate Field — the #8 HR venue in MLB — in this matchup.

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

Andrew Vaughn has primarily hit in the top-half of the lineup this year (100% of the time), but he is projected to hit 7th on the lineup card in this matchup.

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

Lenyn Sosa has a 94th percentile opposite-field rate on his flyballs (37.4%) and has the good fortune of hitting them out towards the league's 9th-shallowest RF fences in today's matchup.

• 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 Chicago White Sox have hit the 1st Five Innings (F5) Team Total Under in 27 of their last 44 games (+7.45 Units / 14% ROI)
• The Seattle Mariners have hit the Team Total Over in 16 of their last 23 away games (+7.95 Units / 30% ROI)
• Randy Arozarena has hit the Singles Over in 14 of his last 25 games (+8.35 Units / 33% ROI)

Seattle Mariners vs Chicago White Sox Prediction

Predicted Final Score: Seattle Mariners 5.04, Chicago White Sox 4.19

• Date: May 21, 2025
• Venue: Guaranteed Rate Field
• Starting Pitchers:
  • Logan Evans - Mariners
  • Shane Smith - White Sox

For more on today's game check out the comprehensive statistics, betting odds, and trends below. Be sure to check out all our free MLB picks here.