Not only is ice hockey the fastest team sport, it also is the only major sport that permits substitutions while play is in progress.

That combination sometimes results in confusion, as was the case Tuesday night in Pittsburgh, when a botched line change by the Washington Capitals helped Pittsburgh's Mario Lemieux score the winning goal in overtime.

Lemieux said he knew the Capitals were in trouble when he saw the chaotic scene in front of their bench. So did Bryan Murray, but a coach is not a puppeteer and Murray could do nothing at that stage but pray that Lemieux would not score, a plea that went unanswered.

At least three Capitals violated conditions for leaving the ice without a stoppage in play. Larry Murphy did not dump the puck deep enough in the Pittsburgh end; Greg Adams and Bob Gould skated off while the Penguins had control in the neutral zone.

The change was so confused that Kevin Hatcher, stepping on to replace Murphy, feared Washington would be penalized for an extra man when Murphy was slow to get off and took himself out of the play.

"Last night, we made a critical mistake and it's something we've had problems with this season," Murray said. "Ironically, Fred Shero two years ago made the comment that we were the most efficient team in the league at making line changes.

"I guess we take it as second nature. We've played 53 games now and we've changed on the fly so many times, there shouldn't be a mistake. We don't practice it a lot, but it's talked about enough."

The Capitals have firm directives in that area, the most important forbidding a change while the puck is heading toward the Washington net.

"The best time to change is when you put the puck deep in the opponent's end," Murray said. "If we have definite control in the neutral zone and there's not a lot of pressure, we can make a controlled line change with two forwards and have the third man wait until the puck goes forward. But those are basically the only times, other than a stoppage of play. You just have to hang tough even if you're tired -- and, no question, our guys were tired last night."

NHL Rule 18, which governs a substitution on the fly, is rather vague, basically forbidding the oncoming player from touching the puck or opponent until the man he is replacing has reached the bench. So far this season, Washington has received six minor penalties for having too many men on the ice, three in successive games from Oct. 31-Nov. 6.

"We cheat so much in that area now," Murray said. "It used to be a guy had to be five to eight feet from the bench before a sub could go on, then it was 10 feet and now everything's left to the official's discretion.

"The Edmonton Oilers really started it. They'd have a guy at one blue line coming off at the same time a guy was leaving the bench at the other blue line. It was a great way to stop -- or start -- a three-on-two and now everybody's doing it. We try to bend the rule as much as we can."

Murray notifies the oncoming line or defensive pairing to be ready for a change and the player must make a judgmental decision to jump out as the man he is replacing heads for the bench. Obviously, it is imperative that a departing player get off the ice and not be tempted to stay out there if the puck heads his way.

All Washington shifts are timed by trainer Stan Wong and Murray considers 45 seconds ideal if the players are working hard. Sometimes, Murray will summon players off sooner, usually with a wave of a paper, if he is trying to obtain favorable matchups. The home team has right of last change during a stoppage, so substitutions on the fly can be a valuable tool to restore desirable pairings.

Murray frequently adjusts lines and defense pairings during a game, complicating life for the players.

"I think it's good for them," Murray said. "They have to pay attention and react. It keeps their heads in the game."