The recent Buffalo Sabres-Winnipeg Jets seven-player-plus-first-round pick trade was a rarity in today’s salary-cap world: a true blockbuster deal involving several very good players, taking place during the season.

It was a surprising and exciting trade, occurring less than three weeks before the NHL’s trade deadline. This deal wasn’t a typically lopsided one seen at this time of year, when a non-playoff team dumps salary on a playoff contender or ships out pending free agents they can’t or won’t re-sign. It was an actual, honest-to-goodness hockey trade which immediately benefits both clubs.

Can we expect more in-season blockbusters like the recent Evander Kane-Tyler Myers swap?

Can we expect more in-season blockbusters like the recent Evander Kane-Tyler Myers swap?

The deal proves it is possible to make a real hockey trade during the season. Since the imposition of the salary cap almost ten years ago, such moves are typically made in the offseason, when teams have more cap space and willingness to make such deals.

Under the NHL current collective bargaining agreement, teams also have the ability to retain a portion of a player’s salary to facilitate a move. That’s allowed teams to swing some deals they were unable to make during the previous CBA. In the Kane-Myers deal, the Sabres agreed to pick up half the remaining value of winger Drew Stafford’s salary.

Other examples include the Florida Panthers picking up part of Kris Versteeg’s contract last season when they dealt him to the Chicago Blackhawks and the Columbus Blue Jackets absorbed part of Marian Gaborik’s remaining salary for last season when they shipped him to the Los Angeles Kings.

Several notable players (Roberto Luongo to Florida, Ryan Callahan for Martin St. Louis) were dealt at, or just prior to, last year’s trade deadline. Such deadline moves were usually uncommon in recent years.

Those trades suggest that some general managers, aided by their capologists, are getting better at working within the constraints of a cap system to swing major in-season deals.

However, it’s a good idea to look at the circumstances leading up to those moves. Without them, the trades wouldn’t have happen when they did, regardless of the ability to retain salary or the creativity of the general managers involved.

In Luongo’s case, he was upset over not being the starting goalie for the Canucks during last season’s Heritage Classic game against Ottawa, resulting in his demand (through his agent) to be traded.The Canucks weren’t a playoff contender and neither were the Florida Panthers, Luongo’s then-former team. He maintains his offseason home in Florida. For some time, the Panthers were interested in reacquiring him but the asking price was too expensive. By the time of Luongo’s trade demand, however, circumstances had changed. Luongo was clearly unhappy and the Canucks were desperate to shed his salary.

So, it wasn’t really a hockey trade but a straightforward salary dump. Had Luongo not been relegated to backup duty at the Heritage Classic, that trade doesn’t occur during the season.

The Callahan-for-St. Louis deal was a hockey trade, but it also came under unusual circumstances. Callahan was slated to become an unrestricted free agent at season’s end and sought a full no-movement clause as part of a new contract. That was a bridge too far for Rangers management.

Meanwhile, St. Louis was pissed off at Tampa Bay Lightning GM Steve Yzerman, also the GM of Canada’s Men’s Olympic Hockey team at the 2014 Sochi Games, for being passed over for selection to Team Canada. Though St. Louis eventually made the Canadian team as an injury replacement, he felt slighted by Yzerman and wanted out of Tampa Bay.

Had Callahan been willing to pass up a full no-movement clause, or if St. Louis hadn’t been upset over the original Team Canada snub, that trade wouldn’t have happened.

In the Sabres-Jets deal, it was akin to the beating of a butterfly’s wings in Africa creating a hurricane in North America. Up until early-February, there was little talk of the Jets trading Evander Kane, who was playing through a nagging shoulder injury. The Jets were trying to hang onto a playoff berth in the Western Conference and media consensus suggested they would move one of their nine defensemen for a top-nine forward.

Myers was the subject of trade chatter all season, but Sabres GM Tim Murray consistently stated he wasn’t shopping the big blueliner, though it was widely assumed he was listening to offers. There was nothing linking Myers to the Jets, or Kane to the Sabres.

Then Kane broke a team dress code, which apparently escalated into a dispute with some teammates, leading to his scratched from a game against the Canucks in Vancouver, his hometown. That sparked speculation Jets GM Kevin Cheveldayoff had run out of patience with Kane and an increase in trade rumors, which weren’t dispelled by his subsequent season-ending shoulder surgery.

If Kane hadn’t violated the Jets’ dress code, he’d probably still be playing through pain in Winnipeg. If the Sabres weren’t in the midst of a massive rebuild, possessing lots of cap space, trade assets and a willingness to add a player who can’t help them until next season, Tyler Myers would still be patrolling the Sabres’ blueline.

Yes, it is possible to stage a blockbuster in-season deal under a salary cap, but you need the right circumstances for such moves to take place. Expect mega-trades like the Kane-Myers swap to remain a rarity in today’s NHL.