NECESSITY was the mother of the reinvention of Mick Malthouse in 2007. For most of the season, Collingwood had no Nathan Buckley, not much James Clement and little of Alan Didak at his most effective. Latterly, Josh Fraser has been in and out. These are cornerstone players.

Chief executive Greg Swann quit. Later, there was the distraction of the Didak issue; later still, the sudden death of Malthouse's father, a jolt for any man. Malthouse himself had ill-health the previous season.

"In some ways, this could have been Mick's hardest year of coaching," said president Eddie McGuire. Instead, it has become, in McGuire's estimation, not just his best at Collingwood, but "one of the best years of coaching of anyone since I've been watching footy".

It began in the manner of an epiphany in round three when the Magpies named three debutants, as many as for all of 2006. They trailed Richmond at half-time, but stormed home to win, so blazing a trail.

Six more debutants appeared in ensuing weeks, including an Irishman who had scarcely seen an AFL game live, let alone played in one. More, and more heroic, wins followed. Collingwood's preliminary final team will feature seven players aged 20 or younger. Malthouse admits that the sangfroid of the youngsters was a lesson even to him.

"They've got a capacity to absorb pressure," he said yesterday. "They're mature young men. They almost demand to be picked because they exude such confidence."

Malthouse said the youthful revolution had been stimulating. "It keeps you alert," he said. "It keeps you busy."

Simultaneously, Malthouse has inspired vintage seasons from Tarkyn Lockyer and Scott Burns, and has Shane Wakelin cavorting about the place like a puppy. Predecessor Tony Shaw, a sometime critic, thinks the way Malthouse had blended the generations into a team, whose defining feature is its evenness across the field, was his finest feat.

"The whole year's been sensational," Shaw said. "Even if they don't win on Friday night, or win the premiership, they've got so much out of the year."

A new team demanded a new way of playing. So did the trend of the competition. The Western Bulldogs had shown the way: it was forward, quickly, at every opportunity. Geelong and the Kangaroos had seized gleefully on the idea.

Malthouse's young Magpies were happy to play to that blueprint. "He's always been a dour, conservative coach," said a rival. "He's become, well, almost a risk-taking coach."

Malthouse's generation of coaches had marked themselves by their sparing use of interchange. This year, the two least-used benches were Leigh Matthews' at the Brisbane Lions (51 interchanges a match) and Denis Pagan's at Carlton (52). But Malthouse has rocketed up the rankings, averaging 61 a game and in last week's semi-final, 101.

Shaw said it indicated that Collingwood now boasted as big a squad of midfielders as any team in the competition, and was using them adroitly. Contemporary and longtime coach Denis Pagan noted how Malthouse had cobbled together a makeshift ruckman out of two fringe players to compensate in Fraser's absences. "He's been able to get the most out of the people he's got," Pagan said. "They're playing to their capabilities."

McGuire said he was not surprised by Malthouse's adaptability. "Far from being the tyrant that people think Mick Malthouse is, he is one of the most progressive, open and inclusive people you could work with," McGuire said. "But ultimately, he has the courage of his convictions to be the boss of his department. The buck stops with him."

McGuire said the coach had cut his cloth according to his material. The grand final teams of 2002 and 2003 were "hard-bodied, tough, aggressive, never-say-die". They were stripped down, rebuilt. "Now he's got a few players coming through with flair, he's loosened it up."

Logically, this radically reshaped team ought not to be playing for a place in the grand final. As a rule, football teams don't manifest readymade, but evolve. Malthouse admitted that he was surprised by the team's exploits at the start of the season."As the year goes by, you get less surprised," he said.

He admitted the Magpies had been lucky in the timely return of key senior players, stiffening the side and allowing him to spell youngsters before exhaustion overwhelmed them. "I expected them to have their ups and downs, and they did," he said. "You've got to manage them. I sent a couple of players home two or three weeks ago."

Malthouse also admitted that he had erred sometimes on the side of over-coaching his young side, notably in an insipid loss to Adelaide in round 22. "We wanted to deny Adelaide what they wanted," he said. "(It meant) we didn't play the game; we played the blackboard." He was pleased with the players in their willingness to follow instructions, displeased in himself to get the instructions wrong.

Malthouse said something similar had inhibited the Magpies in their round-15 defeat by Geelong, their opponent again in tonight's preliminary final. "We didn't play with the instinctive creativity the players have," he said. Whatever else the Magpies do or fail to do tonight, don't expect to see them retreat into their shells.

The coach even has made something of an effort to reconstruct his crusty public image, impressing all at yesterday's news conference with his sanguine disposition. "I sound like his cheer squad," McGuire said. "Well I am. He's been everything I could have hoped for when I got to him to Collingwood. And more."