There are plenty of those names out there of players that I believe were built for the playoffs or at least had the size or skill or were tailored made with their physical style. But why do you think these players dropped the ball in the playoffs all of the time? Just sticking to these specific guys more or less because I am sure there are some opinions on this.
Alexei Yashin - 6'3" 225lbs. a hard right handed shot, played on some good teams too where he didn't have to do all the heavy lifting. Definitely played his way out of the hearts of the Ottawa Senators fans. Granted he wasn't a physical beast out there, but he was big. Looked like he might be onto something in 1997 and 1998 when he was playing on inferior teams that weren't expected to do much. But when he was playing on teams expecting to do more he folded up faster than a deck of cards. 1999, 2001, 2003, 2007 all come to mind, and even though when he was an Islander it wasn't expected that he was going to go far, he still was bad.
Pierre Larouche - Got lucky getting traded to Montreal in the middle of their dynasty. Pete Mahovlich was getting older but I think the Habs are still better off with his well rounded game. Larouche was young, he had huge support on the team, he eventually played on Lafleur's line and yet the two Cups he won he was often a healthy scratch in the playoffs! This is a guy who scored 50 goals twice! He seemed built to play on the Habs, a skilled French player who was a goal scorer. I get that Bowman didn't like him, but he did nothing of note in Pittsburgh and really only had a nice run in 1986 on New York.
Pat Quinn - So I am going the coaching angle here. Quinn was set up pretty good in Philly. I get it, they lost to an eventual dynasty in 1980, but the Flyers had a 35 game unbeaten streak that year. What do you think happened to him in the playoffs? 1992, 1993 both times the Canucks lost when they shouldn't have, I'll give them the magical 1994 run though. Then the Leafs and losing to teams that they were better than (1999, 2002) and not being able to get over the hump against Jersey or Philly either despite always having close series. Can't blame him when he coached Canada, he did well, but what about the NHL playoffs? He's a Hall of Fame coach.
Keith Tkachuk - Was he just in the same boat as a guy like Marcel Dionne where they keyed on him and there was never a lot of support behind him? To me, I don't think so. He also went to St. Louis, and then Atlanta and never did anything there either. Just seemed built for the postseason. Big, strong, good along the boards, good in the corners, could hit, could fight, was tough! And yet you never saw inspired hockey from him in the postseason. He certainly had support in St. Louis. In Phoenix it was all him and Roenick but you saw players of his type perform well and sort of take a series on their back, but he never did.
Joe Thornton - We beat a dead horse with a guy like poor Joe. He is comfortably a future HHOFer, no doubt. You can say in Boston he was younger, but those playoff stats are ugly, and he was a 100+ point guy in Boston and did nothing of note. San Jose he has tons of support. Dionne can't say this, Tkachuk can't say this at least not for that prolonged of time. So what gives? 6'4" 225 lbs. Classic case of a 2nd round bust. His teams were usually good enough to at least get that far but he never took the bull by the horns. Thornton was big, was tough, was a great playmaker and worked well down low and on the cycle (two big things in the postseason). Why was he different in the postseason? Was he not intense enough or too predictable? Did they all expect the pass from him? I don't know, but if there is a player that hasn't an excuse for his playoff failures it is him, because there are definitely times a good series by him catapults the Sharks to greatness.
