Dave Dombrowski has sent a lot of prospects elsewhere since arriving in Boston. Manuel Margot, Anderson Espinoza, Mauricio Dubon, Luis Alexander Basabe, Michael Kopech, and Yoan Moncada could transform the worst system in the game to one of the best had they all been sent to the same place.

As willing as Dombrowski has been to break up the farm system, though, he’s also drawn some pretty firm lines in the sand in each offseason. Last year we heard that Moncada and Benintendi were both untouchable, and they proved to be just that. Obviously Moncada changed, but things change so much from year-to-year that it’s hard to expect statements from late 2015 to hold up into late 2016.

Instead of Moncada, this year has had its own crop of untouchables. They’re just not all in the same place as last year’s. The two who we’ve heard most concretely are off the table: center fielder Jackie Bradley Jr. and now, according to Peter Gammons, catcher Blake Swihart. Benintendi appears to remain on the list, and while Rafael Devers is probably not quite so firmly entrenched—we know Dombrowski balked at having him in the Sale deal, but it’s possible that’s only in conjunction with Moncada or Benintendi—he also seems to be somewhat protected.

Bradley and Benintendi are not all that interesting, at least to me. Both project as important members of the 2017 team that the Red Sox aimed to improve by getting Sale in the first place. I made the point a few times in the run-up to the Sale deal that the Red Sox might risk hurting the future and present alike in trying to go all-in on 2017 if they dealt from their young outfield talent given that Bradley is coming off a five-win season (by fWAR and rWAR alike). And while Benintendi doesn’t quite get the boost Bradley does from his (still strong) glove, he’ll be no small help if he can stabilize left field as an above-average-or-better all-around player.

Blake Swihart is more interesting to me, and I think it speaks as much to Dombrowski’s strategic approach as to Swihart’s quality as a players. Consider again the big names Dombrowski has traded so far, and find one who was anywhere near a low point in their value. Obviously any prospect who proceeds to succeed at the major league level will be worth more than they were in the minors. At this point in his career, Mookie Betts is approaching Mike Trout levels of untouchability (if he is not quite on the same level as a player, he is much cheaper with the same amount of team control remaining). He was certainly nowhere near that when he was crushing Double-A.

But making the jump from minors to majors is the biggest hurdle in all of professional baseball, and when a player stumbles at that point, it can kill their value. Remember Jackie Bradley Jr., once one of baseball’s best prospects, was rumored to have been on the table for Charlie Furbush after the 2014 season. Ben Cherington would deny said rumor, but whether it did almost happen or was simply plausible at the time paints a picture of just how fast stock can fall.

For Dombrowski, it seems that hurdle is also around the time when he’s no longer interested in trading his top guys, at least so long as they remain in that conversation. And it makes plenty of sense. If they succeed, as Benintendi seems to have, then they’re too important to give away at anything less than a premium. If they fail, then their value takes a disproportionately large hit, and it makes more sense to wait and see if they’ll come around than to sell his damaged goods.

That’s what we see in Swihart. His transition to the majors certainly hasn’t been smooth. He’s hit reasonably well, but the Sox themselves have raised the question of how well he can stick behind the plate. At his best he was a prospect who could’ve been a major piece in a Cole Hamels deal. Now we’re closer to vultures swooping in to see what they might be able to snag for pennies.

Eduardo Rodriguez is another player with a similar story, and while we haven’t heard that he’s quite untouchable, the simple fact that he wasn’t involved in the Sale deal where he seemed to many like an obvious inclusion gives some reason to wonder if perhaps he’s not being held back as well. I think his value has probably taken less of a hit than Swihart’s, but at the same time it’s easy to imagine the Red Sox would be selling low after a season which saw Rodriguez struggle with injury.

There’s a few cases which tread this theoretical line of Dombrowski’s, but I don’t think they really cross it. The first is Travis Shaw. He’s attempted the hurdle, and had some very mixed results. Taken as a whole I’m not sure he’s really failed, since he was actually a decently valuable role player in 2016. But having watched the season play out, with Shaw being more-or-less useless for most of the year, it’s a little tough to look at him as a success. The key here is that Shaw was also not one of Boston’s top guys. He was a fringe prospect who stepped up when given an unexpected opportunity in a lost season. Shaw’s value is probably not as high as it was in the middle of May, but it was still above the level it was really expected to be when he was treading water in Triple-A.

The other big one is Yoan Moncada, but that’s easy enough to pass off. Yes, he failed in his first test, but that test was also very short and very early, and doesn’t seem to have really hurt his value any. As evidence: he was just traded for Chris Sale. Maybe Dombrowski was worried by the brief stint and thought Moncada’s value was likely to go down in a year’s time. Maybe he wasn’t. Either way, it was still at a very high point before having faced his crucible in truth.

Otherwise...We have Michael Kopech, who had largely banished the controversy of the preceding year with an excellent second-half. Luis Alexander Basabe is still waiting for his breakout year, but the other side of that is that he might still be waiting for the level that breaks him. We’re expecting him to flip one way or the other at some point, and right now he’s still young enough that scouts are willing to wait and see. Mauricio Dubon just had a breakout season with power that may or may not be real. Anderson Espinoza was having a mediocre year, but still snagged an All-Star pitcher with two years of team control left thanks to having his young age as a ready-made excuse. Manuel Margot had reached his high-point in prospect rankings and wasn’t likely to go higher while essentially stuck waiting for an opportunity in Triple-A. And already one of the big(ish) names dealt last year in Javier Guerra has already fallen off enough that he didn’t even get a mention earlier. That’s one breakout year that seems to have been phantasmal.

Don’t mistake me, this isn’t a claim that Dave Dombrowski is the genius selling high on everyone. It would be a shock if none of these players were eventually worth more than they were on the day they were traded. But he is selling relatively safe. The minors-to-majors jump is not simply a hurdle for a prospect, but a huge gamble for the team calling them up. Given how many top prospects flare out at that step, they’re basically putting all of that player’s value on black for a round of roulette. Dombrowski is going to lose on some of these guys, and win on others. It happens.

Once the Red Sox are the ones to spin that roulette wheel, though, it seems like they’ll hold onto their guys. Sure, if things ever go bad and are back to being sellers at the deadline that’ll change. But so long as they’re aiming to contend both now and in the next year, once they’ve taken that gamble on a valuable piece, they’ll hold onto the rewards, or double down rather than letting a few bad months or even a bad year tank their return on a top name.