Thornton plays on the Sharks top line, but captain Joe Pavelski assumes most of the center-ice assignments. Tomas Hertl, the third natural center on the line, plays most of his time on the wing opposite Thornton.
As he has gotten older, the 36-year-old Thornton has been asked to play on the wing more and more, but don't you dare call him a wing.
"Well, to be honest with you, I think we have three centers," Thornton said of his line. "I don't think any of us are wingers. I think Tomas is a center, [Pavelski] is a center, I'm a center. Whoever takes the faceoff is the center at that particular moment. We all call ourselves centermen. Call me center, please."
Call him whatever you want, but it is working. The line has been one of the most effective in the 2016 Stanley Cup Playoffs, helping the Sharks get past the Los Angeles Kings and Nashville Predators.
Sunday, in Game 1 of the Western Conference Final against the St. Louis Blues at Scottrade Center, the line was the most dominant.
The Blues may have won 2-1, but they know they have to do a better job in Game 2 (5 p.m. PT; NBCSN, CBC, TVA Sports) of containing the opposition's top line. The line scored San Jose's only goal, by Hertl, and generated a dozen shots on goal.
In 13 games this postseason, mostly on the wing, Thornton has 11 points (three goals, eight assists), fourth-most on the Sharks behind Logan Couture (17), Brent Burns (16) and Pavelski (14).
St. Louis coach Ken Hitchcock, who has coached against Thornton for more than a decade and coached him internationally with Canada three times, believes Thornton is a more effective player on the flank because of his unpredictability.
For example, in the third period of Game 1, Thornton was constantly leaving the defensive zone early, hoping to start the San Jose transition as they chased the tying goal. He could not do that if he was still assuming the traditional duties of a full-time pivot.
"Not having to play center ice as a full-time position has allowed him the freedom to move on the ice and create numerical advantages for his line," Hitchcock said. "He's always been one of the guys with the highest IQ in the League. Now he's got that freedom."
The Boston Bruins selected Thornton, a classic power center, with the No. 1 pick in the 1997 NHL Draft. His 6-foot-4 frame, which has been built up to 220 pounds, and raw physical tools to dominate the game were evident. What was not so obvious, at times, was the mental acuity that went along with it.
Often, because of that deadly combination of brawn and brains, the game appeared to come too easily to Thornton. That ease, too often, was interpreted as nonchalance by outsiders.
But those who have coached him, or played with him, know better.
Sharks coach Peter DeBoer had an appreciation for Thornton's game while coaching the Florida Panthers and New Jersey Devils. After spending a full season as Thornton's coach, DeBoer has a much richer understanding of what a special player he is.
"I didn't have an appreciation for how honest a player he is, how hard this guy works away from the puck, how badly he wants to win," DeBoer said. "I don't think until you're around that every day, you don't have a real appreciation for it."
Just how good is Thornton?
"I had him in three [international] competitions [and] he was our best player in all three," said Hitchcock, who was on Canada's staff at 2004 World Cup of Hockey, 2006 and 2010 Olympics. "He was head and shoulders the best player in the World Cup in '04 by a mile.
"I think what you find out in working with him is how competitive he is and how smart he is. He might be one of the smartest players in the League, and maybe in the history of the League. He's been at it a long time. He's still an impact player every night."
Thornton is showing a new generation of fans how good he can be as the Sharks are in the conference final for the first time since 2011.
It has been hard to miss his brilliance, particularly as the primary passer on San Jose's power play.
"I think in general Joe as a player is probably underappreciated just because he spent his entire career, most of his career, on the West Coast," DeBoer said. "If this guy's playing in Toronto or Montreal or New York or one of those markets, he's a living legend. He's that good and he's that impressive a guy."
by Shawn P. Roarke @sroarke_nhl / NHL.com Director of Editorial