Arizona Diamondbacks vs Seattle Mariners Prediction, 5/29/2026 MLB Picks, Best Bets & Odds

Game: Arizona Diamondbacks vs Seattle Mariners

Date: Friday, May 29, 2026

Location: T-Mobile Park in Seattle, WA

TV: MLB.TV

Odds/Point Spread: Arizona (+132) Seattle (-160)

The Seattle Mariners (28-29) host the Arizona Diamondbacks (31-24) at T-Mobile Park on Friday. The line on this matchup has the Diamondbacks at +132 while the Mariners are coming in at -160. The total is set at 8.5. The expected starting pitchers will be Zac Gallen and George Kirby.

As a unit, the Arizona Diamondbacks are notching 4.6 runs per game, which ranks them 9th in the league. They have tallied 255 runs scored and have an OBP of .314. The Diamondbacks have accumulated 103 two-baggers as a team and have knocked 48 balls out of the park. They have compiled 246 runs batted in as well as 453 base knocks for the season, and their team batting average comes in at .248. Arizona owns a slugging percentage of .402 and have been called out on strikes 416 times, while drawing a walk on 169 occasions.

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The Diamondbacks hold a team earned run average of 4.02 for the year (16th in the league), and their staff has rung up 392 batters. Diamondbacks pitchers have surrendered 58 home runs and 241 runs in total (13th in the league). They have walked 162 opposing hitters and their FIP sits at 4.12 as a team for the year. Arizona has allowed 439 base hits (8.1 per 9 innings) and also 217 earned runs. They have accrued a K/BB ratio of 2.42 and the pitching staff holds a WHIP of 1.24.

Diamondbacks bullpen pitchers have come into the game with runners on base 51 times as well as having 69 appearances in high leverage situations. The relievers have a total of 39 holds over the course of the season (6th in the league). The Diamondbacks relief pitchers have a save percentage of 64.0% and have stepped onto the mound in 65 save situations. They have accumulated 16 saves so far this season and have blown 9 out of their 25 chances to get a save. The bullpen pitchers have inherited 75 runners for the year with 25.3% of them crossing home plate. The Diamondbacks have sent 180 relief pitchers to the hill so far this season.

The Diamondbacks have turned 72.0% of balls in play into outs in their 4,374 innings, which has them sitting 4th in pro baseball. The Arizona Diamondbacks have a tally of 1,458 putouts on the year, in addition to 470 assists and 22 errors. Their fielding percentage sits at .989 which is 7th in baseball, and they have turned 36 double plays.

Gallen has taken the mound for 1,061 frames and has tallied 1,100 punch outs in his MLB career. Gallen (69-56 record in his career) has a FIP of 3.59 while facing 4,382 hitters in the major leagues. His ERA is 3.65 (430 ER's allowed) and his WHIP is 1.173. He has given up 904 hits (7.7 hits per nine innings) and has 341 free passes.

The Mariners have a SLG% of .383 and they earn 4.21 runs per contest (18th in the league). They have put up 79 doubles, while taking a walk 208 times and notching 240 runs. Seattle has a total of 66 home runs on the season as well as 234 RBIs. They have been called out on strikes on 504 occasions (7th in MLB) and have totaled 435 base hits. The Seattle Mariners have compiled a team on-base percentage of .317 and a team batting average of .230 this year.

The Mariners are sitting with a team WHIP of 1.217 and are the owners of a FIP of 3.59 as a pitching staff for the season. They have earned a K/BB ratio of 8.60 (485 strikeouts vs 147 bases on balls). They come in at 25th in the league as a pitching staff in total hits conceded with 469. They have yielded 54 long balls and they allow 3.84 runs per 9 innings (5th in baseball). The Seattle pitching staff have conceded 216 runs over the course of the season while having an ERA of 3.54 (199 earned runs relinquished).

Seattle relief pitchers have an inherited score percentage of 16.1% of 56 inherited base runners. Their relief pitchers have taken the field 67 times in high leverage situations in addition to 42 occasions with runners on base. Sitting with 52 save situations, the Mariners have accumulated 30 holds in addition to 8 blown saves. They are ranked 15th in the league with a save percentage of 63.6%, and they have dispatched 173 bullpen pitchers to the mound on the season.

Out of their 4,557 innings on the field, the Mariners have a efficiency on defense of 69.1% (23rd in pro baseball). The Seattle Mariners have turned 52 double plays and have a fielding rate of .988 (8th in pro baseball). The Mariners have accrued 471 assists, 24 errors and have a tally of 1,519 putouts for the season.

So far in his pro baseball career, Kirby has allowed 683 base knocks while he has earned 676 K's in 705 innings pitched. He has given up a total of 281 ER's while earning a WHIP of 1.123 and having a FIP of 3.5. His K/BB ratio is 6.20 and he has gone up against 2,879 opposing batters so far in his pro baseball career. Kirby (50-38 record in his career) has earned a 3.59 ERA and has conceded 8.7 hits per 9 innings.

Who will win tonight's MLB game against the spread or moneyline?

Guy Bruhn's Pick: Take Seattle (-160)

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