Sure, it's fun to talk about what Karlsson could get the Senators IF he's traded, but they have no good reason to trade him. In the end, even if he is traded, they'd need a really top player for him, not just a big package. People will always say, 'hey, look at this: Stamkos, Kucherov, Hedman, and Karlsson all on the same team, wow.' But realistically, Tampa Bay would have to give up one of those three players and add to get Karlsson. Sure, in value Kucherov might be worth as much as Karlsson, if not more, but each player has a different value to their team. For example, two players can be just as good and the value of a trade could be fair, but it doesn't mean either team would do it. So i'm not saying Tampa would trade one of those guys for Karlsson, but Ottawa would need one of them as part of a deal for Karlsson if Tampa really wanted him. If they don't give up one of those guys, they aren't getting Karlsson.
So in the end, Tampa Bay will not have Stamkos, Kucherov, Hedman, and Karlsson all on the same team. If you take a guy like Karlsson or Hedman, we know how good they are on that team, but a) that, so pretty much how they aren't exactly gonna be as good on the other team and b) a lot of GMs overvalue their players. But i don't think it's that they're overvalued by their teams as much as they just want to keep the main guys on the team together, which makes sense. Unless, of course, they got offered something like Kucherov, Point, and a 1st round pick for Karlsson. Is Tampa Bay going to do that? No, not at all, but i'm just saying that's what it'll take to even start discussions about Karlsson. With guys like that, it's very hard to find the right value, so that's what stops major trades like this, but then adding on how the teams never want to trade these guys, that stops it even more. So i don't even understand why Karlsson is on here, because his contract isn't even up until 2019, so it's too early to talk about this in my opinion. Whether it's July 1, July 2, or whenever it is, i think the news will be coming in that Ottawa has re-signed Karlsson to a big extension.
Now if you look at a guy like Pacioretty, who could be available for trade, it would be hard to find the right value. This, which is different (because they shouldn't feel like they need to keep him, he's not a superstar), would still be tricky. Now sure, a Pacioretty deal could get done, though it won't be easy. Every possibility we look at looks like either not enough for Pacioretty, or too much. It always would look bad for one team, good for the other, and then switches around even with a very minor change. Though that's mainly only with guys like Pacioretty, or even Evander Kane (who is a rental), as long as they have a lot of trade value.
So take the thing about the value switching around and all that, and add on the fact that Karlsson is a superstar player, so that stops pretty much any deal that could be made there, as Ottawa would also need a superstar in return. Some guys have more value to one team than another team/player. Karlsson has more value to Ottawa than Kucherov, and Kucherov has more value to Tampa Bay than Karlsson. Who has higher value to an expansion team? That doesn't matter. Whoever has higher value to an expansion team (or any other team, really, just not Ottawa or Tampa Bay), Karlsson has more value to the Senators, and Kucherov has more value to the Lightning. These teams will want something crazy if they're gonna move one of these guys.
I'll look at it the other way around too, so what if Ottawa wanted Kucherov? Tampa Bay would ask for Karlsson+ which the Senators would never do, but that's what the Lightning would need. Trades are not made just because the value is fair. Matthews for Eichel wouldn't happen just because the value is pretty fair. Trades have to make sense for both teams, so Ottawa would never trade Karlsson unless they got something absolutely crazy. Okay, fine, i'm not gonna say they'd never trade him unless they got that return, but right now, before the trade deadline, that's what it would take to get a superstar like Karlsson. They have no reason to trade him other than, 'wow, look at that crazy return, we're getting way more than his value.' And that would be something like Kucherov, Point, a 1st. Not sure if that would actually get the deal done, so maybe Tampa Bay would offer even more (not saying they'd do that, that's just what it would take). But either way, that's the only reason they'd trade him before this year's trade deadline.