Guardians, Mariners In MLB Tuesday's Best-Bet Daily Double
There's a full slate of MLB action Tuesday. Since there is nothing to bet on, and I don't count the Women's World Cup, I'm getting down on some MLB. My two looks Tuesday are in the Cleveland Guardians vs. Cincinnati Reds and Seattle Mariners vs. Kansas City Royals matchups.
MLB Tuesday Tilts
Cleveland Guardians (57-62) at Cincinnati Reds (62-58)
Neither one of these lineups hit left-handed pitching well. I'd give Cleveland an edge in the starting pitching matchup and the Guardians have much better relief pitching.
Guardians starting LHP Logan Allen (5-5, 3.55 ERA) has a better HR%, strikeout rate, and FIP ("fielding independent pitching") than Reds starting LHP Graham Ashcraft (6-7, 4.95 ERA). FIP is the most predictive pitching metric.
With that in mind, Cleveland's bullpen has 4.00 FIP (ranked 10th). Whereas Cincy's bullpen has a 4.55 FIP (ranked 26th), according to FanGraphs.

Guardians C Bo Naylor celebrates with closer Emmanuel Clase after defeating the Toronto Blue Jays at Progressive Field in Cleveland. (Jason Miller/Getty Images)
Most of the sports betting market is backing the Reds Tuesday because they have more to play for. Per Pregame.com, more than 80% of the action is on Cincinnati's moneyline (ML) but the line is moving toward Cleveland.
However, the Reds are just 3-7 over their last 10 games and 8-12 in the past 20. So it's not like Cincy is playing good baseball entering Tuesday.
BET: Guardians -108 ML (up to -120) at DraftKings

The Cleveland Guardians' ML odds at the Cincinnati Reds in MLB Tuesday, Aug. 15 from DraftKings.
Seattle Mariners (63-54) at Kansas City Royals (38-81)
The Mariners have a massive 3-phase edge over the Royals in starting and relief pitching and hitting. Mariners RHP Emerson Hancock (0-0, 1.80 ERA) makes his 2nd-career start. Kansas City counters with RHP Jordan Lyles (3-13, 6.13 ERA).
Hancock is Seattle's top pitching prospect. The Mariners called up Hancock to help with their playoff push. Lyles is perhaps the worst starting pitcher in MLB. He leads the AL in ER allowed (86) and leads the majors in losses.

Mariners starter Emerson Hancock delivers a pitch during the 2nd inning against the San Diego Padres at T-Mobile Park in Seattle. (Stephen Brashear-USA TODAY Sports)
Also, Seattle's bullpen ranks 2nd in FIP (3.62) whereas Kansas City's bullpen ranks 24th (4.47). The Royals won the series opener Monday 7-6 in extra innings. I.e. both bullpens are taxed so that gives the Mariners a bigger edge since each have less arms to use.
Furthermore, Seattle's lineup out-ranks KC's vs. right-handed pitching in wRC+ (103-86), wOBA (.313-.300), (.170-.154) and BB/K rate (0.34-0.28), per FanGraphs.
Lastly, the Royals are the best team in MLB to fade on the run line (RL). Kansas City's RL bet-against return on investment is 10.7%. The next closest team is the New York Mets with a 7.2% bet-against RL ROI.
BET: Mariners -1.5 (+110) RL at DraftKings (down to -105)

The Seattle Mariners' RL odds vs. the Kansas City Royals in MLB Tuesday, Aug. 15 from DraftKings.