TORONTO -- When Brian Burke traded two first-round picks and a second-rounder to the Boston Bruins in September 2009 for Phil Kessel, he believed the Toronto Maple Leafs would make the playoffs in 2010 and 2011.

When they didn't, the Bruins got the Leafs' No. 2 pick that became Tyler Seguin and the No. 9 pick the next year that became Dougie Hamilton. Fans at TD Garden in Boston would often chant, "Thank you, Kessel," for the deal that looked like it could be incredibly lopsided.

"All this debate about the Kessel deal -- was it worth it? Was it not worth it? -- I find it amusing," Burke said in April 2010. "I got news for you, we're all going to know at some point. This is no different than two farmers side by side arguing whether they plant soy beans or corn. And they argue and one guy plants corn and one guy plants soy beans.

"Guess what, we're going to know at some point who won. We don't have to argue the whole time while the plants grow for God's sake."

With six years of hindsight, the Leafs and Bruins both lost the trade, with the beneficiaries being the Pittsburgh Penguins, Dallas Stars and Calgary Flames. Toronto trading Kessel on Wednesday checked the last box on every player from that deal being traded again.

Here's a look at how it all unravelled:

JULY 4, 2013

The Bruins won the Stanley Cup in 2011 with Seguin as a bit part who was scratched at times during the playoff run. Two years later, he was their third-leading scorer in the lockout-shortened 2013 season. That was his first on a US$34.5-million, six-year deal.

But just before the start of free agency, Boston traded the 21-year-old to the Stars with Rich Peverley for wingers Loui Eriksson, Reilly Smith and Matt Fraser and defenceman Joe Morrow. Then-Bruins GM Peter Chiarelli implied off-ice issues contributed to the trade.

Seguin has been more than a point-a-game player for the Stars since, outscoring Smith, Eriksson and Morrow's combined Bruins output 161-115.

The Oilers claimed Fraser off waivers in December.

MARCH 2, 2015

Boston used the second-round pick in the Kessel trade, 34th overall in 2010, to select forward Jared Knight. The former London Knights standout couldn't crack the NHL and spent time with the Providence Bruins of the AHL before being sent to the Minnesota Wild on deadline day for Zack Phillips.

JUNE 26, 2015

After the Bruins missed the playoffs for the first time since 2007, Chiarelli was fired and assistant Don Sweeney promoted to GM. Not long after taking the job in May, Sweeney let colleagues around the league know that Hamilton was available.

Hamilton set career highs in goals, assists and points this past season, but Sweeney said the defenceman wasn't comfortable signing long-term with the Bruins. So he found a trade partner in the Flames, acquiring the 15th, 45th and 52nd picks in the 2015 draft for the 22-year-old.

Add winger Zachary Senyshyn, centre Jakob Forsbacka-Karlsson and defenceman Jeremy Lauzon to the Kessel trade tree.

Days after that trade, Hamilton signed a $34.5-million, six-year deal with Calgary -- the same the term and value Bruins signed Seguin to in 2012.

"We were comfortable, more than comfortable, parting with the package that we did and then I'm real happy that we've got him under contract for six years and part of our core moving forward," Flames GM Brad Treliving said.

JULY 1, 2015

Brendan Shanahan witnessed a flawed core in his first year on the job as Leafs president, and he promised changes. The first swing of the wrecking ball came by dealing Kessel to the Penguins for prospects Kasperi Kapanen and Scott Harrington, winger Nick Spaling, a third-round pick and a conditional first-rounder.

Six years after Burke's gamble backfired, Penguins GM Jim Rutherford put lottery protections on the first-rounder. Toronto only gets the pick if Pittsburgh makes the playoffs.

Essentially, the Leafs got back two first-round picks (Kapanen and a future selection) and a second (Harrington) for the 27-year-old Kessel.

"It just worked out that we were looking for players of the future and Pittsburgh was looking for a player that could fit their needs in the present," Shanahan said. "At the end of the day both clubs sort of set forth on what their direction was."

The Leafs set forth into a long-term rebuild as the Penguins cranked open their Stanley Cup window with Kessel alongside either Sidney Crosby or Evgeni Malkin. He's signed for seven more years.

The $1.2 million of Kessel's cap hit over that stretch is the last remnant of the 2009 trade on the Leafs' books.

Later in the day, the Bruins added Jimmy Hayes to the Kessel lineage by trading Smith and the contract of injured forward Marc Savard to the Florida Panthers for the restricted-free-agent forward.