Both clubs are playing in their first MLS final but their 'barren runs' have been of starkly different character.

Until this season, the Sounders were consistently the bridesmaids while the Canadians simply risked becoming the league's laughing stock.

Seattle, who average a league-high 42,000 fans at each home game, have made the playoffs in every season since entering the league in 2009 but never made it to the championship game.

In contrast, Toronto, who came into MLS in 2007, failed to make the post-season for eight straight years, breaking that run last season only to be knocked out by Canadian rivals Montreal in the first round, despite investing heavily in some big-money signings.

The club has recently expanded their BMO Field, with a 36,000 capacity for Saturday's game, and tickets sold out within minutes of going on general sale.

While last year's final featured two relatively small-market teams with the Portland Timbers beating Columbus Crew, this encounter should generate much higher interest among television viewers.

Toronto coach Greg Vanney played for the LA Galaxy against DC United in MLS's first ever title game in 1996 and believes this clash is set to be the most impactful in the league's history.

"This will be the biggest MLS Cup, yet, to date. Obviously, two countries are represented with teams, and two of the major market teams, in terms of fan support, media support, all those kinds of things.

"So I think this'll be, in terms of coverage and attention ? I think it'll probably be the biggest MLS Cup that we've seen so far,? he said.

'Big Three' boost Toronto

Toronto have taken full advantage of MLS's 'designated player' ruling which allows for three players on contracts that mostly do not count against the salary cap.

Diminutive Italian international forward Sebastian Giovinco was brought from Juventus while Americans Jozy Altidore and Michael Bradley returned to the league from Europe creating an NBA-style 'Big Three'.

It has taken time for the investment in that trio to be complemented by a rounded squad but this season has seen the side find the kind of form that made them title contenders from early in the campaign.

Seattle have been without their biggest name, forward Clint Dempsey since August, with the US international having been diagnosed with an irregular heartbeat.

But in the absence of the former Fulham and Tottenham striker, homegrown youngster Jordan Morris has shined in attack.

Seattle recovered from a poor start to the season which cost their only coach from the MLS-era, Sigi Schmid, his job in late July.

Assistant Brian Schmetzer took over and the club's form enjoyed a major upturn, significantly helped by the arrival from Boca Juniors of the talented Uruguayan international midfielder Nicolas Lodeiro, who has quickly become one of the most watchable players in the league.

"We haven?t made it easy on ourselves this year but that just makes it sweeter," said Sounders striker Herculez Gomez, looking back on the disappointing first half of the campaign.

In the often physical contest that MLS games tend to produce, the outcome of the game could well depend on the battle of two shaven-headed enforcers in midfield.

US national team captain Michael Bradley's form is crucial to Toronto while tough-tackling Cuban Osvaldo Alonso gives some real bite to Seattle's midfield.