It's about who has done it.

Until he has done it, he is unproven.

And it doesn't matter whether the "he" is the Stars' Marty Turco, who had a great regular season before his ankle problem popped (swelled) up. Or Roman Cechmanek, who has posted even better numbers for the Flyers this season. Or feisty Dan Cloutier, who just kept making the clutch saves for the Canucks until his sprained knee became a problem. Or even the Lightning's Nikolai Khabibulin, whose credentials otherwise seem deeply established.

GOT GOALTENDING?

EASTERN CONFERENCE Ottawa: Patrick Lalime was strong in the playoffs a year ago (1.39 GAA), and look where his team sits, in part because of his consistency. For what it's worth, his last two starts have been aberrations. New Jersey: Although he has come down to earth in March, Martin Brodeur is a more worthy Hart Trophy candidate this time than the fellow who won it last year, and he's playoff proven. Tampa Bay: John Grahame's acquisition lessened some of Nikolai Khabibulin's workload. But the Russian hasn't played in the postseason in four years -- and never has gone beyond one round. Until you do it ... Philadelphia: The Hitchcock system has helped him look good, of course, but Roman Cechmanek was sterling when the Flyers couldn't score. But he's a lot like Khabibulin; he's never played more than one round. Toronto: Yes, Ed Belfour has been strong. His puckhandling is an improvement over Cujo, and for all his quirks, he can tune into his different wavelength and be strong again in the playoffs. Washington: This isn't a knock on Olaf Kolzig, but he will deliver what he always has -- steadiness and quality play, which once helped get the Caps to the finals. But steal it? No. Boston: OK, it's not like Byron Dafoe was a Rock of Gibraltar, which is why he now is a Thrasher of Atlanta. Jeff Hackett is capable of stepping up, but that's no certainty, either. N.Y. Islanders: Garth Snow was mercurial during the Flyers' '97 run to the final, and has played one postseason game since. But the Islanders at least settled the situation by trading Chris Osgood and putting their faith in the journeyman, who has played well. WESTERN CONFERENCE Detroit: After Dominik Hasek's departure and a so-so regular season, Curtis Joseph made progress in winning over teammates and skeptics during the Wings' recent run. Here's his chance to clinch the deal. Dallas: Even if Marty Turco finally recovers from the right ankle injury that has kept him out five weeks, he probably won't have time to sharpen himself before the postseason opens. Vancouver: As well as Dan Cloutier has played, he still doesn't strike you as the long-range answer, does he? And his late-season battle with a sprained right knee doesn't bode well. St. Louis: This is a minority opinion, and we know some folks still think the Wings won despite him. But Osgood has been through the wringer and hoisted the Cup overhead, and after the Blues' goaltending mess all season, he gives them a better shot. Colorado: After a horrible start, at least by his standards, Patrick Roy has that swagger back. Now if Tony Granato can just convince him not to handle the puck so darned much ... Minnesota: See Unproven Theory. Dwayne Roloson has taken over as The Man and has had a great year, but he was awful for Buffalo in his one previous shot. His run with the Lowell Lock Monsters two years ago doesn't count. Anaheim: Jean-Sebastien Giguere has had a heavy workload, and his total playoff experience is zip. Edmonton: If it gets to crunch time, Tommy Salo still might be seeing Belarus shots in his sleep. Remember, he hasn't been in a playoff game since Salt Lake.

"It," of course, is great playoff goaltending.

The given is that the standards of excellence and success boil down to which players are smiling and which ones are grimacing and speaking through clenched teeth, if speaking at all, in the handshake line after the final game of a series. The ultimate measure is if each skater encounters the opposing goaltender and at least is thinking something like: "If not for this son-of-a-(nice couple from Saskatchewan or wherever), we'd have won this thing."

And the supreme validation is the Stanley Cup overhead. It means sixteen victories, sixteen nights when he might not necessarily have outplayed the guy at the other end, but been good enough, resilient enough, larcenous enough, even spectacular enough, to have allowed the puck in fewer times than the other guy. A few of those nights probably involved overtime, when any minuscule mistake or misjudgment can end the game, instantly, and it doesn't matter one iota what has happened the rest of the game -- whether you have faced 11 shots and allowed three goals, or been a sheet of plywood erected over the net.

Going on too much about this, of course, risks belaboring the obvious. ("Well, no kidding, Sherlock.") But, quick, no fair peeking or painstakingly going back over the years in your head. Just a quick, gut reaction: How many times in the past 23 playoff seasons, or since the move to 16 teams and a full four-round bracket, has the Conn Smythe winner been a goaltender?

(While you're thinking, briefly, remember that if you get the answer wrong, you're voted off the island and don't get to roast marshmallows with an actress who was the second banana in a bad '80s sitcom. Or however that goes on trash TV.)

The answer: Seven times by five goalies. Patrick Roy (three times), Mike Vernon, Bill Ranford, Billy Smith and Ron Hextall. And if you didn't remember the last two, guard your shins, because a slash from one of the combative goalies is coming.

Even in a discussion of an era that encompasses Gretzky and Lemieux and Trottier, the initial thought here was that the number would have been greater.

But it wasn't.

Among other things, that list shows that greatness is not a prerequisite. With beard dripping under the mask, Ranford helped show that there was Cup Life after Gretzky (and Grant Fuhr). Vernon has marginal Hall of Fame credentials, and he was the goalie of record for two Cup champions, but is he great? No. Smith won the trophy in the final year of the Islanders' dynasty, and he deserved a nod for the body of work over the quadrennium, if nothing else. A goalie can either be just good enough for a team demonstrably better than everyone else, or bad enough to get his team beat. But the former is a lot harder than often is acknowledged, and the most recent case study can be labeled the Osgood Phenomenon.

It's just a different animal. You can come out of nowhere to prove you're up to it, too, as Roy somewhat did as a rookie in 1986, especially stoning the Rangers in that memorable series, and long before he began to be zealous about practice work and conditioning. So this is not going to involve a definitive rejection of the possibility that Turco and Cloutier, if they get well, or Cechmanek, could prove capable of holding up to the challenge of the postseason run.

They could.

But until they do it ...

In the playoffs now, this becomes a mind game more than ever. Games virtually every other night. Detailed video study, painstakingly studied. Chartered flights back and forth, when the discussions can be of the money tally in the card games, but the thoughts and words can be about how that other goalie is getting into their heads. Geez, just shoot high on him; get traffic in front of the net; rattle him. And the same things are said to the fourth estate and dutifully recorded and trumpeted.

Quality isn't necessarily measurable, either, by anything other than wins.

Stats? Sure, they're significant, but this can be as much about shrugging off the aberrational night and coming back strong in the next game to regain control of the series -- and the opponents' psyches -- as it is about a relentless stoning. That requires a resiliency of spirit. It involves an ability to dismiss doubt, arising both in the goalie's own mind and those of his teammates. Yes, regardless of the goalie's track record, a stretch of playoff problems can be debilitating, and sometimes only because teammates can be either overtly or subconsciously thinking: "We're just not getting the goaltending."

So as this postseason approaches, the smart money, so to speak, is on those who have done it. Roy in the West, despite his spectacular flameout a year ago, and Martin Brodeur in the East.

Can you win a Cup despite, rather than because of, a goaltender's work? Well, that's what you often hear about that 1998 Red Wings triumph, with Chris Osgood in the crease, but that underestimates the magnitude of both the pressures and the challenges. Osgood held up to them, then hoisted the Cup overhead, and he wasn't the only reason for the Wings' subsequent lack of championship success over the next three years.

So from this corner, the view is that Osgood gives the Blues as much of a chance in the postseason as Sean Burke would have. And maybe more than that. He has done it. Most likely, too, he will be going up against Colorado and Roy in the first round. As sparkling as Roy's playoff work has been over the years, his reputation as a money goalie has been bruised, and that notorious Game 6 Statue of Liberty gaffe against the Wings last spring will remain memorable. Last weekend, when Colorado played in Detroit, the Joe Louis Arena crew showed highlights from previous games against the Avalanche, accompanied by Louis Armstrong's "What A Wonderful World." The climax was that Game 6 miscue. The Wings will hold that over his head, and not drop it.

The playoff crease is no place for the fragile of heart and spirit.

Terry Frei is a regular contributor to ESPN.com. His book, Simon and Schuster's "Horns, Hogs, and Nixon Coming," is available nationally.