CHICAGO -— Rule 74 sounds simple enough. Too many men on the ice, and you get a two-minute penalty.

Turns out it's a bit more complicated, and a miscalculation becomes even more costly this time of year.

Seven of the NHL's 16 playoff teams were among the league's most penalized clubs for having too many men on the ice, according to STATS. Chicago, which begins its title defence Wednesday in St. Louis, was second with 13, followed by Detroit (11), Minnesota (10) and the New York Islanders (10), and Anaheim, Dallas and San Jose in a group at nine.

It may seem like a small number over the course of an 82-game season, but power-play opportunities take on added importance in the playoffs while the mixing and matching of lines becomes even more frequent. So it likely will come up more often this week as teams prepare for the post-season.

"Yeah, absolutely," Chicago star Patrick Kane said. "I think we've always been a team that's probably been whistled more than the norm as far as taking too many men on the ice penalties and you know, that's something we don't want to do obviously. ... That's one of those things we have to be aware of."

When it comes to the rolling changes at NHL games, the departing player must be within five feet of his bench before the substituting player can come on the ice. The penalty is most often called when a player either plays the puck or makes contact with an opposing player while getting on or off the ice.

"You know when your guy is close enough for you to go on, but again, if you're going to change and there's a puck that's coming in your direction, it's human nature to try to play it," Wild forward Jason Pominville said. "Then sometimes your guy is already on the ice, so there's not much you can really do about it.

"I guess it's just being alert and knowing the situation. If you're hopping on the ice and seeing your guy might have a chance to play it, stay off. But it's tough. It's not an easy one, for sure."

Communication is key, but that part is easier said than done during a frenetic game, especially in a loud arena in the playoffs.

"There's so much line-matching now that coaches are trying to see which line is coming up for (the other) team, and sometimes the call gets changed last minute and you either don't hear it or you don't have enough time to redirect yourself," Capitals defenceman Karl Alzner said.

Of the 13 too many men penalties for the Blackhawks this season, only four of the ensuing power plays were successful for the opposing team. But three of the goals were particularly costly.

One of them led to Mark Stone's go-ahead goal in the third period of Ottawa's 4-3 overtime victory on Dec. 3. Another one cleared the way for Ryan Getzlaf's overtime winner in Anaheim's 3-2 victory at Chicago on Feb. 13. And there was David Backes' tying goal in the third period of St. Louis' 3-2 shootout win on March 9.

The Blackhawks (47-26-9) finished third in the Central Division, four points back of the second-place Blues (49-24-9).

"I think every one of them has a different flavour, a different interpretation," Chicago coach Joel Quenneville said.

"Sometimes we get six guys for no reason. I'll take the hit for those," he continued. "There's always a reason why. But this year we've had more than our share, which we're not happy about."

Chicago also had 13 too many men penalties last season, up from nine in 2013-2014. The number of too many men penalties across the NHL increased from 224 last season to 228 for this campaign, according to STATS.

After Anaheim's win on Feb. 13, Getzlaf said he felt Chicago pushed the envelope all night long with its line changes.

"I think the referees did a pretty good job," he said. "Obviously, I'm going to say that and they're probably going to say the opposite. I thought they were pretty close all night and it cost them in overtime."

Whatever the issue, Quenneville just wants his players to be vigilant when it comes to the possible penalty.

"We feel being aware and being sharp, communicating coming into the bench, coming off the bench, the awareness factor is just as important," he said.