A couple of weeks ago, James Shields gave up 10 runs in a start against the Mariners, prompting the Padres owner to call the team’s performance embarrassing. He even cited Shields by name, saying that the pitcher — 18 months into a four year, $75 million contract — should be embarrassed by his outing. It would be the last start Shields would make as a Padre, as a few days later, San Diego shipped him to the Chicago White Sox in exchange for a replacement level arm and a 17 year old who is a long way off from the big leagues. In order to facilitate the deal, the Padres agreed to pick up $31 million of the remaining $58 million on Shields’ deal, giving the White Sox an innings eater at an innings eater price.

At least, that was the thought. In both of his first two starts in Chicago, Shields has been a disaster, giving up 14 runs and lasting only seven innings combined between the two outings. Combined with his final start in San Diego, Shields has now allowed 24 runs in his last three starts, and it’s not like it was just bad luck; he has a 13.48/8.46 FIP/xFIP over those outings as well. It’s likely that Shields will turn things around, as he’s not the worst pitcher baseball has ever seen, but you have to think the White Sox are already wondering if the Padres sold them a lemon.

After all, it wouldn’t be the first time a perfectly reasonable sounding plan — a contender taking on part of an albatross contract in order to get a fairly priced veteran without surrendering much value in return — went sour. In fact, if you look at the recent history of deals made in the same vein as the Shields trade, they’ve almost all been disasters for the acquiring team.

Last summer, the Blue Jays tried a more grandiose version of this type of trade, picking up Troy Tulowitzki from the Rockies. Just a year removed from putting up +5 WAR in 91 games, the Rockies finally relented on moving their star shortstop after watching him run a career-worst 104 wRC+ over the first half of the season. The Blue Jays saw a chance to buy low on a guy who was the consensus best shortstop in baseball when he was healthy, and because his stock was down, they even managed to get Colorado to agree to take Jose Reyes‘ contract in the exchange, lowering Tulowitzki’s effective salary in the process. They had to give up some talent to get him, but by getting Colorado to pay down Tulo’s deal by taking Reyes, the Blue Jays thought they had a chance to get a high-level performer at a reasonable cost.

Except Tulowitzki has only gotten worse since getting to Toronto. He ran a 91 wRC+ in the second half of 2016 in the regular season, then was mostly unproductive in the playoffs, putting up just a 66 wRC+ in October. This year, he put up a 79 wRC+ and replacement level production overall before landing on the disabled list, and his loss of contact skills suggest that the Blue Jays probably didn’t buy low on a star after all; instead, they bought into the middle of a rapid decline. I would imagine that, even with Jose Reyes’ value plummeting to zero after the trade due to his domestic violence issue, the Jays would still like to a have do-over on that trade if they could.

Before the Tulo trade, there was the Matt Kemp disaster, in which the Padres got the Dodgers to subsidize $32 million of the remaining $107 million on Kemp’s contract, and thought they were getting an elite slugger at a fair market price in the process. Instead, Kemp’s been one of the worst players in baseball since arriving in San Diego, and that trade is one of the primary reasons the Padres attempt to contend went nowhere. A year and a half later, Kemp is back on the block, with San Diego looking to see if anyone wants to make another trade of this type, but they’re going to have to eat almost all of Kemp’s deal to move him, most likely; his value has gone down to something near zero.

Before the Kemp trade, Texas tried this trick with Prince Fielder. The Tigers had too many 1B/DH types as it was, and Texas had too many second baseman, so the two teams hooked up on a swap that sent Fielder to Texas for Ian Kinsler, with the Tigers covering $30 million of the $168 million left on Fielder’s deal in the process. Now in his third season in Texas, Fielder has produced -0.2 WAR since joining the Rangers, is potentially on the verge of losing his job, and the Rangers still owe him another $80 million, even after factoring in the payments from the Tigers. Even if Kinsler hadn’t gone back to being one of the best second baseman in baseball — he has done just that, however — this deal would have been awful for Texas; with Kinsler’s revival, it’s turned out to be one of the worst trades any team has made in a very long time.

Before the Kemp trade, there was the epic Dodgers-Red Sox swap back in August of 2012, where Boston agreed to surrender the still-valuable Adrian Gonzalez as long as LA also agreed to take on Carl Crawford and Josh Beckett’s contracts as well. This one isn’t as clear cut, as the Dodgers did end up getting a couple of productive years out of Crawford in 2013 and 2014, so their buy-low idea did work to some degree, though Crawford still wasn’t worth the money the Dodgers took on to acquire him. Of course, they also got the reasonably-priced Adrian Gonzalez in the deal by taking Crawford, so this one hasn’t been the total disaster the others have been, though it still seems pretty clear that the Red Sox got the better end of that trade; they immediately took the money they saved in the salary dump, spent it on better free agents, and won the World Series the next year.

In fact, of all the pay-down-an-overpriced-salary trades in recent history, the only one I could find where the buyer clearly came out ahead was the Pirates acquisition of A.J. Burnett. Prior to the 2012 season, the Yankees were desperate to dump Burnett, and so they shipped him to Pittsburgh, but agreed to keep $20 million of the remaining $33 million of his contract on their books. The Pirates paid just $13 million 2012/2013 seasons, and he was one of the better pitchers in the National League in both years, helping push the Pirates back into contention for the first time in forever. That deal was a huge win for Pittsburgh, and a perfect example of what teams are hoping for when they make these acquisitions.

But besides one example of Ray Searage fixing a broken pitcher, the recent history of these types of deals is kind of miserable for the buyer. If you go back 13 years, the Yankees came out way ahead by picking up A-Rod from Texas after they decided to move his contract, so it’s not like it’s never happened in MLB, but lately, the deals have worked out far better for the team avoiding a coming collapse than the buying team that thinks they’re getting value by buying low on a former star.

Of course, the past is no guarantee of future results, and so maybe the team that takes on the majority of Ryan Braun‘s contract this summer will fare better than other recent teams that have tried this trick. But if you look at the current leaderboards, who is the best performing player in 2016 that got traded in a deal where the seller agreed to pay down a good chunk of a long-term contract in order to make the deal happen? As best as I can tell, it’s Melvin Upton Jr, who was dumped on the Padres — note the theme here — in the Craig Kimbrel trade. The Braves aren’t explicitly paying any of Upton’s contract, but they did take Carlos Quentin’s contract back in the trade, and gave up a positive-value Kimbrel at a talent discount in order to move Upton, so they surrendered value to get the contract off the books, even though they aren’t writing checks to San Diego to cover Upton’s deal.

But when a 31 year old hitting .246/.301/.411 is the best producer of a a group, you know the group has some problems. In reality, the guys who have had their contracts paid down to create trade value have been miserable failures this year, and a team thinking about making this kind of gamble on a guy like Braun might want to remember how this plan has worked out with Tulowitzki, Kemp, and Fielder. Or maybe even James Shields. If the seller is so anxious to get rid of their aging former-star that they’ll pay you to take the guy, it might be time to consider whether they know something that you don’t, and are attempting to get off the train right before it wrecks.