Who sits? Who plays?

It won't be visible in Claude Julien's hand tomorrow night when he is behind the Bruins' bench for the first time, because as indelicate as it sounds, and as authoritative as it is, the essential tool of the trade is not a tangible asset.

"The hammer," said the 47-year-old Julien, about to embark on an odyssey that has proven the ultimate in incomplete journeys for those who have preceded him in Boston the last 35 years. "Every coach has to have that. The players have to know there are consequences if they're not accountable - you hear that word a lot these days, accountable. They have to be accountable, follow direction, both on the ice and off the ice, and they have to know that [the coach] is it - he makes the last decision."

As in all sports, the art and science of coaching have changed dramatically in hockey the last three decades. The Bruins, meanwhile, have cashiered their coaching staff at a dramatic pace. Julien will be their third head coach in the three opening nights since the end of the 2004-05 lockout.

Only time will tell if Julien and the rest of his coaching crew have the right blend of game planning and motivation to return the Bruins to respectability and relevance. The Art Ross days of a lone authoritative figure behind the bench, designing and implementing systems, directing all practices, and being all things to all players have gone the way of leather skates and bare-faced goalies.

Beginning with the likes of Fred "The Fog" Shero, who added Mike Nykoluk as his assistant with the bullying Flyers of the 1970s, and the legendary Scotty Bowman, the trusted Claude Ruel forever by his side in his Montreal glory days, coaching has become a complex, multilayered exercise. On most NHL teams today, the head coach has at least two assistants, as well as a goalie coach, and "off-ice" assistants, including those who specialize in video and strength and conditioning.

For example, Julien has top aides Craig Ramsay and Geoff Ward behind the bench, and to help direct practices. Bob Essensa is back as goalie coach, joined by fellow returnee Doug Houda, now the eye-in-the-sky coach, radioing observations from the press box. John Whitesides is back for his seventh season as the club's strength and conditioning coach, and Brant Berglund is in his fourth year as video coordinator.

"It's different now, more complex," said Bowman, 74. "It's more of a coaching staff now, and much more in depth, from the bench right on down to the video guy. These days, the coach will have a recipe of things he wants from the video guy during a game, and the computer gets loaded up, they shoot it all, and then they're off on a plane to the next game, watching the tape, dissecting it . . . way more technical."

Bowman, with nine Stanley Cup rings, more than any other coach, is widely considered one of the best coaches of our time. Ditto Al Arbour, who directed the Islanders to four consecutive Cups (1980-83). Both were known for keeping their players' attention by awarding ice time based on merit, and merit only.

"Bowman was the master coach," said Mike Keenan, the former Bruins bench boss who is back on the job this season with the Calgary Flames. "What I learned from him was, and it may sound simple, it's essential to have the right people on the ice at the right time. Ask someone how long a hockey game is, and most everyone will say 60 minutes. But from a coaching perspective, it's 720 minutes - that's six players, or positions, on each side, and two teams over 60 minutes. What you do as a coach, how you [apportion] those minutes, is essential."

Those minutes end up the force behind the hammer. That part of the game has not changed. Coaching structure and hierarchy have evolved, and coaches vary in their approach and personality, but ultimately, the job boils down to who suits up on a given night, who gets on the ice for which shift, and how many minutes each player logs.

Veteran maneuver

Bowman, who led the Canadiens to five Cups and four consecutively (1976-79), recalled one opening night in that glorious run when he decided not to dress veteran returnee Yvon Lambert. Lambert, said Bowman, was a "useful" player, but he had a less-than-average training camp, and it was the coach's decision to send a message to Lambert, as well as the rest of the Habs vets, that no one should ever get too comfortable.

"One thing I always believed as the coach," said Bowman, "make sure they expect the unexpected." Another Bowman coaching tenet: "You can't be miserable all the time, but I made sure I was miserable when we weren't playing well."

On this night, though, the unexpected was outrageous. Lambert was a favorite in the room, and Bowman had a rookie in his place. Ten minutes before the game, Bowman recalled, Ruel told him he must change his mind, because of unrest in the room. Icons Guy Lapointe and Serge Savard knocked on his door to tell him the same.

"They said, 'You can't do this,' " recalled Bowman. "And all I said was, 'Yeah, we can.' "

Sensing he needed to underscore his point - the opening faceoff drawing near and the room's unrest at a boil - Bowman made his way to the dressing room.

"I said, 'Guys, I have to talk to you. We have a big problem tonight,' " he said. "They're all wondering what's going on. And I say, 'Instead of dressing 18 players tonight, we're only allowed to dress 17. It's a league decision. One of you will have to sit out. Do I have any volunteers?' You know, no one said a word. I think they got the message about who makes decisions."

Clarity is key, on many levels. That's true on the ice, where Julien constantly preaches his aim is to "eliminate all gray areas - players want it black and white," and off the ice, even before the coach is hired, according to Brian Burke, general manager of the Cup-winning Anaheim Ducks.

"As the GM, you have to know the kind of hockey you want to play," said Burke, who quickly made Randy Carlyle his coach upon taking over the Ducks' front office. "You have to make sure the coach shares that vision. We're an old-school team. We play north-south. We bang. We trade chances. We want to entertain the fans."

To that point, said Burke, he wants a motivated, sometimes animated coach. Burke doesn't dispute that X's and O's are important, but they are often the domain of one of the assistant coaches. The more essential job of motivating and energizing players has to fall to the head coach.

"I want a guy with energy and passion," said Burke. "There can be 18,000 people in a building and I can be up in the press box and still hear Randy barking back there. I like that. You'll hear coaches say, 'Oh, I think we played great tonight . . . we only gave up five scoring chances.' Gee, great. Those are the guys back there with their arms folded all night. Let me tell you, it's hard to get $100 a seat for that kind of game. A guy like that is never going to work for me."

Communication factor

The Blues last season were dead in the water under coach Mike Kitchen, and were 7-17-2 when team president John Davidson and GM Larry Pleau realized it was time to make a change. Out went Kitchen and in came ex-Kings coach Andy Murray, one of the game's more structured, motivational coaches. The Blues went an impressive 27-18-11 the rest of the way.

"So much of it is timing," said Davidson. "In our situation, things had been mostly the same around here for years. It needed to be stimulated. Time has a way of corroding things. We needed a cultural change, a different dynamic. Not to disparage anybody, but it was like we were introverted here."

Davidson, a former goalie who went on to be one of the game's top analysts, takes a state-of-Missouri approach to coaching. He wants the guy back there to show him motivation.

"You have to have a guy who motivates, and that has to be the head coach - because he is the one who calls all the shots," said Davidson. "Andy is demanding, very demanding, but at the same time, he is not demeaning. If you're demeaning, OK, you can still be good, but that's going to catch up. The most important thing is that the players know the coach has total control. The coach has to know, too, when to loosen the reins a little bit, because players have to be 'right' between the ears. This is a tough, physical, demanding game, and if your head is burdened, it's all the tougher."

Disgruntled players lead to phone calls, most commonly player to agent, and then agent to general manager. In today's game, the coach who doesn't take the extra time to explain why a player isn't dressing, or why his ice time has been diminished, usually can expect to hear from someone.

"Communication is key," said local agent Matt Keator, who represents Boston captain Zdeno Chara among many NHLers. "It's true, players love black and white, but if he makes a bad play out there, it's important to tell him what's wrong. I think the biggest problem in the industry today is that a lot of coaches grew up playing in the '70s and '80s, when no one talked to you. But kids today, they're in a more communicative world. They want to know. How else are they going to get better?"

Agent Steve Freyer, who represented Ray Bourque, agreed with the need for communication. But he also noted there is a fine line, that a player who is constantly asking for clarification can be perceived as the "squeaky wheel - a guy who is only caught up in his own game and doesn't care about the team."

Bourque, said Freyer, appreciated the approaches of former Boston coaches Terry O'Reilly, Mike Milbury, and Pat Burns.

"All tough guys . . . no-nonsense guys who had proof of success," said Freyer. "They had the respect of the team. They were involved back there. And if they said, 'You're dogging it,' they had the moral authority to say it."

Final say

Following a nonplayoff season in 2005-06, what Vancouver GM Dave Nonis labels a "disastrous" 42-32-8 season under Marc Crawford, the Canucks brought in former Canadiens coach Alain Vigneault to run their bench. It took a couple of months for players to adjust to a new coach and new system, said Nonis, but eventually, the players began to thrive under "the new culture."

The Canucks recorded a franchise-high 105 points, played two playoff rounds, and Vigneault was named the NHL's coach of the year.

"What Alain told the players is exactly what he did," said Nonis. "He let them know, 'I don't care what name is on the back of your sweater, or if you make $6,000 or $600,000. If you play well, you'll get ice time.' And he said, 'If you aren't doing the job, I also won't yell, and I won't ridicule. I just won't play you.' That was a big, big change for us."

However, the firm-handed Bowman, recalling the words of legendary Habs GM Sam Pollock, said, "I can take a lot of aggravation from a .300 hitter, but not nearly as much from a .200 hitter." Every room has its player hierarchy that the head coach must engage and indulge, in part so the best players will confirm the coach's message and "sell" it to the rest of the roster.

"But they have to understand, too," said Bowman, "I'm here to win games, not friends."

Keenan, nicknamed "Iron Mike" for, shall we say, his democratic approach with veterans and rookies alike, agrees a coaching essential is to engage the veteran leaders in the room. In New York, where he coached the Rangers to the Cup in '94, Keenan had the inimitable Mark Messier to carry that message.

"A great leader," lauded Keenan. "He had the go-ahead to shape the team in the room. And his trick was, he made the role players feel like they were the most important guys on the team. No one had to tell Brian Leetch or Adam Graves how important they were. I'm talking about guys like Greg Gilbert, Joey Kocur, and Jay Wells. Players love ice time. They want it. They need it. They thrive on that. And to win a Cup, you need all of them doing something crucial with their minutes. It can be as elementary as the one or two shifts Greg Gilbert is going to give you so Graves can sit on the bench and reload."

And, said Keenan, not to forget one point.

"All that said," he mused, "excellent goaltending really helps."