Statistically, the New York Yankees and the Boston Red Sox were fairly comfortably the two best teams in the American League. Because statistics don’t matter and we play 162 games for no reason, perhaps the third and fifth best teams in the AL — the Cleveland Guardians and the Tampa Bay Rays — are playing in the ALCS.
I don’t just say that for dramatic effect: Statistics actually don’t matter. You know what does, though? Wins, and the Rays paced the AL in that category this season with 98 of them despite never once having the underlying metrics of a 98-win team. They outperformed their Pythagorean Expected Win Total by eight entire wins, but that obviously doesn’t matter. They won 98 games, got a bye, smoked the Yankees like a rack of ribs in the ALDS and now are four wins away from their second World Series berth this decade. And only one team can stop them: the “underdog” Guardians. And I think they can.
The Guardians measure up quite well to the Rays

Crafting some kind of numerical framework for why the Guardians can beat the Rays wouldn’t be that hard, but it wouldn’t really be in good faith either. They aren’t really underdogs, and while betting markets have the Rays solidly favored (-170 at a lot of books), projection models have it much closer, with ZiPS going 51/49 in favor of Tampa. If I were to chef up some number soup that explained the matchup, every data point that showed an advantage for the Rays would have to ignore one for Cleveland. Both have great pitching staffs, solid bullpens and fairly vulnerable lineups. All year, the Rays and Guardians profiled as good-not-great offensive teams with above-average pitchers; Tampa just happened to win 13 more games.
I asked Ben Clemens in his FanGraphs chat (which was just randomly happening as I was writing this) what he thought the best argument was for the Guardians, and he responded with the above ZiPS projection and by saying, “Great pitching staff, Rays offense is kinda vulnerable, win a few close games thanks to Cade Smith.”
Smith notwithstanding, I think the Rays offense being vulnerable is your best investment thesis for the Guardians. They didn’t exactly beat the Yankees by slamming down seven to 10 runs per game, and let’s not forget they won Game 1 by nearly no-hitting the Bronx Bombers in a 1-0 victory. Their offense definitely can be had, and they essentially only roll out three above-average hitters: Junior Caminero (an absolute beast), Yandy Diaz and Jonathan Aranda. It’s a lineup that can be exposed and pitched around, and will rarely threaten a large number of home runs.
The Rays offense is not scary enough to make them prohibitive favorites

The Rays will have the advantage early in the series coming off several important rest days, but the Guardians have plenty of quality arms out of the bullpen and an offense that really has woken up lately. Jose Ramirez didn’t have his best season by any respect, but if he gets hot specifically right now? That could be real trouble.
Perhaps the best argument for why the underdog Guardians can win is that they just … aren’t underdogs, and refuse to let the sports betting public their influence our discourse on this topic. I don’t think the Guardians are worse than the Rays, because they aren’t, and they can definitely win the series. Sometimes the best arguments have the fewest numbers.
