New York Team(s) Sign Sidearmer(s)

Ah, relievers. Can’t predict them, can’t live without them. Between the changing demands of a modern game and the fact that bullpen arms seem to fluctuate randomly between unhittable and unreliable, everyone always needs more relievers. Both New York teams, set at many other positions, made moves to bolster their bullpens yesterday. The Yankees are signing Darren O’Day, while the Mets are adding Aaron Loup (pending a physical).

Let’s address O’Day first. Only two days ago, the Yankees traded Adam Ottavino to the Red Sox for a bag of baseballs. Actually, it was worse than that: they traded Ottavino and a prospect and $850,000 to the Red Sox for future considerations. As Dan Szymborski detailed, the Yankees made that trade to dodge the Competitive Balance Tax, but doing so left a right-handed hole in their bullpen.

One thing that no one can dispute is that Darren O’Day is right-handed. That has, in fact, been his calling card for 13 major league seasons: O’Day breaks right-handed batters down, end of story. Over his lengthy career, he’s held them to a .248 wOBA, with a 27.5% strikeout rate doing most of the heavy lifting. His sidearm delivery is a rarity these days, and it turns righties into… well, into whatever you want to call Bobby Dalbec on this swing:

That goofy (though not in a skateboarding sense) arm angle turns an 86 mph fastball into a devastating weapon, a pitch that batters think will hit them in the leg before it explodes up and away. He complements it with a sweeping slider he commands well to his glove side, a useful counter when hitters start to adjust to the unexpected release point.

The last time O’Day allowed even league average production to opposing righties was in 2011, when he faced only 43 of them. ROOGY is an overused term — at this point, even LOOGYs hardly exist — but O’Day might be the rare pitcher who fits the bill.

By using O’Day strategically against righty-heavy patches of the opposing lineup, the Yankees hope to get a steady diet of strikeouts and weak fly balls. Unlike most sidearmers, O’Day works up in the zone, something which surely adds to batters’ confusion. It’s not so much the velocity, the location, or the delivery; the combination of everything is simply too strange to deal with.

You might think that a sidearmer throwing high in the zone to lefties — three batter minimum and all — would undo all the good that O’Day does against righties. You’d be right — O’Day has been brutal against lefties as his career has worn on. Since the beginning of the new lively ball era in 2015, he’s allowed 1.5 HR/9 against lefties, good for a 4.67 FIP (ERA isn’t really compatible with splits like these). For comparison, his FIP against righties over the same window is a stellar 2.61.

The onus is on the Yankees to find good spots to use such a situational reliever, but the opportunities will certainly be there. Consider the rosters of the Yankees’ three division rivals (sorry, Orioles). The Blue Jays signed righties George Springer and Marcus Semien to join righties Bo Bichette, Teoscar Hernández, and Vladimir Guerrero Jr., while the Red Sox have only three lefty batters on their roster. The Rays — well, yeah, the Rays will be a problem. Even then, though, sending O’Day out to face a dangerous righty with two outs will often be worth the gamble — he’s bad against lefties, but not enough to offset his mastery of righties.

At $2.45 million, O’Day doesn’t need to set the league on fire to meet expectations. The Yankee bullpen is strong at the top — Aroldis Chapman, Zack Britton, and Chad Green provide quantity and quality, and two of them are even lefties. If O’Day can contribute 40 to 50 innings of right-handed filth, the Yankees will be pleased — that’s Ottavino production at a quarter of the price.

Speaking of New York teams signing situational relievers, the Mets signed Aaron Loup, who will become the only left-hander in an already-excellent bullpen. Calling him reverse O’Day misses the mark — he throws harder and doesn’t display such extreme platoon splits. Still, though, bringing in a southpaw in an all-right-handed bullpen tells you what the Mets want from Loup: come in against opposing leftys, sit them down, and tread water against the righties.

Okay, fine, there’s one major similarity between Loup and O’Day:

Like his new borough neighbor, Loup comes at hitters from a novel angle. Unlike O’Day, he lives in the bottom of the zone with a sinker. He complements his fastball, which sits around 92 mph, with a cutter, curve, and changeup that he uses almost exclusively against righties — the last time he threw a changeup to a lefty was in 2017.

The terms of Loup’s deal haven’t yet been disclosed, but they’ll likely closely mirror O’Day’s contract. So, too, will his role, though this time I mean mirror in the sense of the same thing in reverse. Loup will face dangerous lefties and then try to survive against the righties who follow them, shielding the Mets’ top relievers from the slings and arrows of outrageous Juan Soto highlights.

Neither of these deals are going to turn into wild, runaway success stories. Neither player is going to garner Cy Young votes. But teams need innings out of the bullpen, and both the Mets and Yankees are in competitive divisions. Filling those innings with quiet competence might be the difference in a game or two, and a game or two might be the difference in the playoff race.

How might these signings backfire? It all depends on what you mean by “backfire.” The most obvious downside is that O’Day and Loup might simply not be very good. O’Day throws a mid-80’s fastball and Loup is a 33-year-old reliever who struck out only 22.9% of opponents last year. It would hardly be shocking for one of these pitchers to be a roster casualty within the year — a few bad weeks, a pressing need for 40-man space, and that might be that.

Short of that, the downsides are all opportunity cost. If you’re out of the Loup market, you might be in the market for an exciting call-up from Triple-A. Giving innings to known and medium quantities is all well and good, but it lowers your odds of making exciting discoveries with that roster spot. The odds of O’Day turning into the next hot reliever du jour are essentially nonexistent.

For two presumptive playoff teams, however, that’s a negligible downside. It’s fun to discover new young relievers, but the downside is no joke: they might be bad! For teams far from contention, volatility is good. If you’re right in the thick of things, though, reliever volatility is definitely not where you want to be. By lowering their odds of failure, the Yankees and Mets are increasing their chances of success. Not bad for two sidearmers.