Derek Jeter couldn't lead his Yankees to victory, but that doesn't make him a choker. Doug Pensinger/Getty Images

We need to get something straight about choking, which is merely the most misunderstood concept in all of sports. It has become a catch-all term, applied to any player or team who: A) blows a huge lead; B) fails in a crucial moment; or C) loses an important game more than once. Whenever someone falls into any of those three categories, we turn into that annoying Rob Schneider character from Saturday Night Live. The New York Yankees give away a 3-0 lead in the ALCS? Chokesters. Scott Norwood misses a last-second, game-winning field goal in the Super Bowl? The choke-man. Phil Mickelson comes up short in major after major? Choke-o-rama.

But not everyone who fails when we expect them to succeed is a choker. In fact, most of them aren't. The Yankees are the latest team to have the tag slapped on them unfairly, a result of their unprecedented collapse against the Boston Red Sox in the ALCS. There are any number of words that accurately describe the Yanks' failure -- "humiliating" comes to mind -- but "choking" is not one of them. A choker is a player or team who loses because the pressure of the moment adversely affects their performance. There is no way that could logically be said of the Yankees. They have thrived under pressure so often that it's absurd to think that they suddenly crumbled because of the magnitude of the moment.

Yankee closer Mariano Rivera, nearly infallible in the postseason for close to a decade now, didn't blow two saves against the Sox because he suddenly turned weak in the knees. Teammates like Derek Jeter, Bernie Williams, and Jorge Posada should likewise be immune from accusations of choking. They've succeeded in the clutch so many times that when they fail, it makes no sense to suggest that they suddenly developed a case of nerves.

Among elite athletes, choking is a rare but usually unmistakable occurrence. The purest example I've seen first-hand came in the 2000 NBA playoffs, when the Portland Trail Blazers squandered a huge fourth-quarter lead in the seventh game of their series against the Los Angeles Lakers. It wasn't that the Blazers lost, it was how they lost. As their lead dwindled and the L.A. crowd grew louder, the Blazers looked scared. Suddenly they couldn't make the easiest shots, shots they had been making all game, all series, all season. I remember Portland's Rasheed Wallace continually looking up at the scoreboard clock as if he was praying that time would run out before the Lakers could catch them. The Blazers were overwhelmed not so much by the Lakers but by the intensity of the circumstances. That's choking.

Choking is a mostly mental phenomenon that affects physical performance. Just so we're clear, a few examples:

Remember the panicked look on Chris Webber's face when he called for a timeout that Michigan didn't have in the NCAA championship game? That was a choke.

Bill Buckner's boot in the 1986 World Series? A physical mistake at the worst possible time, but not a choke.

The heavily favored Lakers losing four straight to the Detroit Pistons in the NBA Finals last season? Massive collapse, yes. Choke, no.

Golfer Jean Van de Velde, blowing the 1999 British Open with terrible shots and even worse decisions for a triple bogey on the final hole? Paging Dr. Heimlich.

Sometimes accusations of choking can do a disservice to the winner as well as the loser. Suggesting that the Yankees choked, for instance, diminishes the accomplishment of the Red Sox. The Sox were simply the better team for the last four games of the series, just as they appear to be the better team in the World Series against the Cardinals. With a 2-0 lead, it appears that the Red Sox are finally going to bring a World Series title to New England. You can feel their fans' excitement. You can sense the anticipation building. But a friendly word of caution to the Red Sox nation, who surely know this better than anyone:

The circumstances are perfect for a choke.

Sports Illustrated senior writer Phil Taylor writes about a Hot Button topic every Monday on SI.com.