Mariners vs. Royals prediction and odds for Thursday, Aug. 17 (George Kirby should dominate)

George Kirby should continue his dominant August on Thursday against the Kansas City Royals.
Seattle Mariners starting pitcher George Kirby (68).
Seattle Mariners starting pitcher George Kirby (68). / Bruce Kluckhohn-USA TODAY Sports

The Seattle Mariners have erased a slow start to the 2023 season by playing some terrific baseball since the All-Star break. 

The team is now just one game out of a wild card spot in the American League, and it has a cupcake afternoon matchup with the last-place Kansas City Royals on Thursday. 

Kansas City has the third worst run differential in Major League Baseball this season, and it’s dropped two of the first three games of this four-game set. 

Reliever Angel Zerpa (1-1, 7.71 ERA) will make his fifth appearance of the season and first start on Thursday. While Zerpa will be used as an opener, he may be able to give the Royals some length. He pitched four innings in relief in his last outing and three innings back on Aug. 5. 

The issue? He allowed nine combined runs in those two outings. 

Seattle counters with young righty George Kirby (10-8, 3.11 ERA) who allowed just three hits in nine scoreless innings in his last game and has allowed just six hits and one run in 16.0 innings this month. 

Can Seattle take this series and creep closer to a playoff spot? Here’s a look at the latest odds for Thursday afternoon’s matchup: 

Mariners vs. Royals odds, run line and total

Mariners vs. Royals prediction and pick

Both of these teams have hit the ball well over the last 15 days, with the Royals ranking second in Major League Baseball in OPS over that stretch while Seattle is ninth. 

However, I think there is too big of a discrepancy on the mound to look past in this game. 

Kirby has been terrific in his second Major League season, posting a 3.17 Fielding Independent Pitching to support his 3.11 ERA. He’s had a few outings where he’s struggled, yet he’s allowed three or fewer runs in 18 of his 23 starts in 2023. 

This month he’s been especially sharp, shutting down the Los Angeles Angels and Baltimore Orioles. While he didn’t get a single run of support against the Orioles, that should change on Thursday. 

We don’t have much to go off of with Zerpa since he’s only pitched 9.1 innings this season, but the early returns aren’t good. He’s been rocked in both of his longer outings, with his best game coming in his Major League debut – two scoreless innings against the New York Mets. 

Even if Zerpa does pitch well, it’s impossible to trust this Kansas City bullpen, which ranks 29th in baseball with a 5.24 ERA. 

Kirby, on the other hand, has the No. 3 bullpen in the league (in terms of ERA) backing him up. 

I’ll gladly take Seattle to cover on Thursday and win the series. 

Game odds refresh periodically and are subject to change.

Find Peter Dewey's betting record here.