The Seattle Sounders are the envy of Major League Soccer - and the sports world as a whole.

They have the largest and arguably most passionate crowds in American soccer, they have dominated Open Cup competition, and they have established themselves as a force in the regular season. And they've done this all in a relatively short period of time: they only started competing in MLS in 2009.

But with the MLS playoffs kicking off, all eyes will be focused on whether or not Seattle can finally get their hands on the one thing that continues to elude them: MLS Cup.

For all of their success, the Sounders have underachieved when it matters most, despite having had some of the most talented players in the league. Kasey Keller and Freddie Ljungberg passed through their doors (Keller is now a broadcaster with the team) and the current roster includes the explosive trio of Eddie Johnson, Freddy Montero and Mauro Morales.

They've made the playoffs each season of their existence, but that's as far as they've gotten -- Seattle has gone out in the first round each and every time.

So can the team everybody wants to be like finally get the championship they most covet?

"I think this team definitely has what it takes to make a run at the championship," coach Sigi Schmid said after the team's regular season finished Sunday. "There is enough quality on the field, enough quality on our bench, and the desire is definitely there."

Schmid should know, having won two MLS championships in his 13-year coaching career with the LA Galaxy (2002) and Columbus Crew (2008). But there are many unanswered questions for his Sounders before getting started in their home-and-away series with Real Salt Lake on Friday night -- the same RSL side that beat the Sounders 3-2 on aggregate in their playoff matchup last year.

First: which Sounders team will show up in the postseason? They were the best team in the league early in the year, but then stumbled before regaining their form to finish third overall in the western conference.

Second: are they healthy enough? Leading scorer Johnson was hurt in their regular season finale and is questionable, while veteran defenders Leo Gonzalez and Patrick Ianni are both out at least for the first playoff game.

But Seattle does hold one advantage on the competition, and it's a doozy. Their home support is the envy of American sport.

Since the franchise took the field, they have continually set records in attendance. This season, they are averaging 43,144 at home, by far the best in MLS. (That's also an average that would put them among the best clubs in Europe and South America.)

"We have to use our crowd as motivation," explained team captain Mauro Rosales, who has experience playing for world-renowned clubs River Plate of Argentina and Ajax of Holland. "To have that number of fans supporting us is something we always consider an advantage for us. We have to think of them, our own families and know that one good game at home can give us the possibility to advance (in the playoffs)."

"(The crowds in Seattle) are very similar to those (at River Plate and Ajax) - the same passion. I feel it in Seattle and we have to take advantage of it. It's an advantage to have that type of fan base with that fanaticism that have the urge to support us."

Schmid knows he has that advantage, and hopes his team can make it pay off.

"Obviously we need to win at home and we need to get something on the road," Schmid said.

"We are at home first. Last year it was the opposite, so we need to do the same kind of job that (Real Salt Lake) did on us last year (When they won 3-0 at RSL)."

If the Sounders can pull it off, it'll give rivals their biggest reason to envy them. If they cannot - then another year of questions about their ability to finish the season will start again.