At the end of 2018, Blake Treinen was riding high. He finished sixth in AL Cy Young voting, a placement befitting his absolutely outrageous season. He threw 80 innings of 0.78 ERA, 1.82 FIP relief, the best relief season by RA9 WAR in the 21st century and the sixth best by fWAR. He earned a $6.4 million salary in arbitration, and entered 2019 as the anchor of a fearsome bullpen.

Ten days ago, the A’s chose not to tender Treinen a contract. The dominant days of 2018 looked far gone; Treinen was below replacement level this year, and it’s easy to see why: his walk rate spiked from 6.7% to 13.9%, while his strikeout rate concurrently fell from 31.8% to 22.2%. Where a year ago he was an elite strikeout pitcher with a below average walk rate, this year he was just bad. His nine home runs allowed were also a career worst, and the combined package just didn’t work at all.

So when the A’s non-tendered him, it was somewhat surprising but not unthinkable. They run a shoestring operation, and spending on relievers is a risky way to spend scarce resources, particularly when said reliever was so bad last season. He wasn’t due much of a raise in arbitration — MLB Trade Rumors projected a $7.8 million salary — but the A’s decided they’d be better off finding relievers elsewhere and saving the money.

Yesterday, everything went all funny. The Dodgers signed Treinen to a one-year, $10 million deal, and, well — you’re not supposed to get non-tendered and then make more as a free agent. The whole reason teams crave controllable players so much is that arbitration awards tend to come at a discount to free agent prices. Non-tenders happen when teams expect a corner case in arbitration (generally for closers and dingers, but also award wins and prior salary awards) to create a distorted market.

In essence, the A’s non-tendered Treinen because they valued him below $7.8 million dollars (or thereabouts). The Dodgers clearly disagree, and disagreements like that are increasingly rare in today’s model-driven world. If information were perfectly known, the A’s would have gone through arbitration and then traded him to the Dodgers, who would have been willing to give something (money, if nothing else) in return for a cheaper Treinen.

That’s really interesting, and the places where team preferences don’t perfectly overlap are theoretically fascinating — but the real interesting thing here is what will become of Blake Treinen in 2020. Seriously, let me say it again — Treinen’s 2018 was the best relief season of the century, and his 2019 was below replacement level. What in the world is up with that?

First of all, Treinen wasn’t a true talent 0.78 ERA reliever in 2018, because no one is a true talent 0.78 ERA reliever. That said, his peripheral stats were off the charts that year, and all of them cratered in 2019. Let’s take a closer look at his pitch mix to see what happened.

An accounting of Treinen’s arsenal has to start with the sinker. Treinen’s game is unique in that he relies on a one-seam fastball, an ersatz two-seamer that behaves mostly like a sinker but with more horizontal break; that break led to a 29.2% whiff rate on his sinker in 2018, second only to Zack Britton among pitchers who threw 200 sinkers. In 2019, the pitch changed in a few ways: it lost 1.3 mph and actually added horizontal carry, while also “sinking” less (it rose more relative to spinless motion).

The net result was a pitch that, while it still had excellent movement, didn’t quite dive out of the path of bats with the sudden darting verve it had in 2018. His whiff rate on the pitch fell to 25.3%, and with less sink, his groundball rate also declined. As Al Melchior noted, he also started leaving the pitch higher in the zone, which put more pitches in harm’s way, exacerbating his strikeout and hard contact issues.

The net result wasn’t a disastrous pitch; Treinen’s whiff rate was still among the top 10 in baseball. But much of his game was built around the ability to throw the pitch with impunity; he flooded the zone with it and his complementary four-seam fastball in all counts. In 2018, he threw 56% of his fastballs in the strike zone. When he was behind in the count, that rate spiked to 64%. Treinen threw you fastballs and dared you to do anything with it.

It’s hard to know whether he lost control or started nibbling due to his declining groundball rate, but 2019 was very different. He threw only 45% of his fastballs in the zone, and the number didn’t increase when he was behind in the count. Throw that many fastballs with that low of a zone rate — the league threw fastballs in the zone nearly 59% of the time when behind in the count — and walks are sure to follow.

That’s pretty much the Blake Treinen story. He was a one-pitch marvel who built everything off of his devastating sinker. When he couldn’t use that pitch in the same way he used to, the rest of his game couldn’t hold up. His four seam fastball is average, mainly a way of ambushing batters sitting on the sinker, but it’s not a pitch you could build a game around.

His two breaking pitches are really variations on a theme; he throws a slider and a cutter that break against his sinker to varying degrees, with the slider the better of the two, but neither stands out on its own. They’re excellent complements, but Treinen isn’t a slider pitcher; he’s a sinker pitcher who can sneak a slider by.

The Dodgers are making a specific bet with this contract. If Treinen’s sinker returns to form, he’s a bargain. There are reasons to believe it’ll work; he was bothered by injury for most of 2019, including an IL stint at the end of June. His release point was all over the place, presumably out of a combination of searching for his lost form and dealing with injury. His velocity dip was largely post-injury; an offseason of rest could fix that. But until he pitches in 2020, we can’t know.

If Treinen rebounds in 2020, he’ll play a key role in the Dodger bullpen. Kenley Jansen heads the unit, but past that it’s largely duct tape, bubble gum, and strongly felt prayers; Joe Kelly and Pedro Báez will be heavily involved, as will lefty specialist Adam Kolarek in a world of three batter minimums. They have minor league arms and swingmen to pick up some of the slack, with Dustin May, Kenta Maeda, Tony Gonsolin, and Ross Stripling all able to chip in as needed, but they’ll all be needed as starters as well, and there’s real value to elite relievers.

From my perspective, this is a smart gamble by Los Angeles. They’re so likely to win their division that it’s reasonable to think about playoff rosters, and through that lens, taking a chance on getting a dominant relief pitcher seems like a wise use of resources. If Treinen can’t recapture his old form, they can move on after 2020. If he gets his groove back, he’ll bolster the weakest unit on a great team at a reasonable cost.

For the A’s, this move must sting. They survive by scrounging for every possible edge and accumulating value in every transaction they make, one red paperclip style. But several teams were rumored to have offered Treinen a deal around the Dodgers’ offer, which means Oakland simply misjudged his market. It’s not a giant loss, but it can’t feel good to express your valuation of a player so strongly by non-tendering them, only to have the rest of the league tell you they would have paid more.

For Treinen, of course, $10 million is $10 million. He’s probably experienced a whirlwind of emotions in the past few weeks. First, he expected to make in the neighborhood of $8 million in arbitration. Then he expected to make less, because he was unemployed, and a team that could have locked him up for around that number chose not to. Then he made more than that, choosing between several offers no less, to play for one of the best teams in baseball.

The offseason transaction merry-go-round had a happy ending for Treinen. The Dodgers hope that 2020 is similarly fortuitous. Only time will tell, but a deal that looks like a savvy gamble for the team and an unexpected $2 million windfall for the player is hard not to like.