Both the Sharks and their No. 1 center may have shed those reputations after Saturday night.
The Sharks, who haven't made it past the second round since 2004 despite dominating during the regular season, became the first team to reach the conference finals by eliminating the two-time defending Western champion Detroit Red Wings, winning 2-1 to complete a five-game series victory. They did it with a huge performance by Thornton, who scored San Jose's first goal in Game 5 and found Patrick Marleau for the game-winner 6:59 into the third period.
"I kind of caught him out of the corner of my eye getting the puck, and I was able to stop and find a spot," Marleau said. "He's going to make those passes all night, and it's up to me to get the shots off and find the back of the net."
Thornton finished the series with 3 goals and 8 points, the best single-series performance in his career. He has already matched his single-postseason highs with 3 goals and 11 points. Two of his eight assists have set up winning goals by Marleau -- in OT in Game 3, and again on Saturday.
He's also excelled in the little things -- using his size to control loose pucks, winning faceoffs (71 percent in Game 5) and giving the kind of extra effort that wins games at this time of year.
His coach has noticed.
"When you look at Jumbo as the playoffs have evolved, he's felt more and more comfortable playing a role outside of being a pure setup man and scorer," Todd McLellan said. "He's played extremely physical, he's been really good in the faceoff circle, he's penalty-killed, his turnover ratio has really gone down.
"We couldn't be happier for him. He's one of the individuals I talked about who had to shed a reputation (for underachieving) -- whether fairly or not -- and to this point he's done a real good job."
So have the Sharks, whose reputation as playoff underachievers was magnified last year when they were knocked out by Anaheim in the first round after winning the Presidents' Trophy for having the best regular-season record.
"This is a very, very big win for our organization for a lot of different reasons," McLellan said. "One, obviously, is the opportunity to continue playing in this playoff year. Two, is to shed some of that reputation that we have supposedly earned in the past."
While beating any team in the playoffs is an achievement, Thornton recognizes that advancing to the NHL's final four by beating Detroit -- the symbol of playoff success -- makes the Sharks' accomplishment that much more special.
McLellan, whose resume includes a Stanley Cup ring with the Wings in 2008, said beating his old team showed how much his current club has grown.
"I don't know if it's a changing of the guard," he said. "They are a very good team. They've been to the conference finals the last couple years.
"The fact that it was a team that has been to the Stanley Cup Finals the last couple years, a team that has quite frankly has had our number over the last little bit. And then the ability to recover from the shellacking we took in their building. I think there were more questions there."