THE time of sparing football innocents is gone. More kids are playing AFL, sooner. And they're having greater immediate impact.

Typically, 75 to 80 new faces appear in any one season, mostly towards the end when non-finalists experiment with their lists. This year, 51 have made their debut already, 18 in round one, both records. Carlton, North Melbourne and Fremantle all have fielded five greenhorns. But, instructively, Geelong has played just one, once, and St Kilda, the other runaway ladder leader, none. This fits the axiom that a football club is forever either contending or rebuilding.

But for football's Gen Y, it is not simply about getting a guernsey. Seven have played every game. Stephen Hill and Daniel Rich have blitzed. Brendan Whitecross and Jack Ziebell are averaging 18 touches a game. Taylor Walker has kicked 15 goals. David Zaharakis kicked the winner on Anzac Day. These kids are here not merely to take a mark, but make one.

Not so long ago, the novice's first-season philosophy was that he would be happy just to get a game. If he did, noted Brisbane Lions coach Michael Voss on Sunday, the usual and understandable attitude was: "How good is this? I'm playing league footy. I'm standing next to Nick Riewoldt."

No longer. "The young kids that have come in are not happy with just that," said Voss. "They want more. That's so pleasing. They want to make a valuable contribution to the team, not just turn up and play."

Jason McCartney, once a boy star himself, now an assistant coach at the Australian Institute of Sport football academy, is witness to this evolution. "If Stephen Hill came to North Melbourne in the mid '90s, Denis (Pagan) would not have been able to play him for 12 months," he said. "He would have been killed."

McCartney said that a player with Hill's physique would not have survived the physical buffeting. Nor, before the era of high bench rotations, would he have had the necessary endurance. A generation previously, when the game was not nearly as closely scrutinised, grizzled elders would have seen to it that a player as precocious as Hill met with an early accident. "The game's changed a lot," said McCartney.

The changes run deep. In McCartney's time, the learning was on the job. "I might have been videotaped once in my career," he said. "Clubs didn't have development programs. You were thrown in with the rest. The strong survived, the weak fell by the wayside." McCartney was lucky at least that he had a man's body and already had played men's football. Others were lost, or did it bruisingly hard.

Now, young footballers get a thorough grounding in the game, its theory and practice, beginning long before they become professional. Nutrition, conditioning, recovery, biomechanics, visualisation; all are on the curriculum.

It used to be said of football that it is not rocket science. Now it is.

Not until his last playing year, under Dean Laidley in 2003, did McCartney get a glimpse of this. "Denis was a fantastic coach, and had a massive influence on us," he said. "But we played a pretty simple style of footy. In the modern game, you really need to understand not only what your role is, in your area, but what the roles of the other players are.

"I've learned things through the program here that I never learned when I was playing. For us, it was just about playing. It was never about diet, nutrition, decision-making. Recovery was eight or 10 laps on a Sunday morning.

"I marvel at just how complete the education process is now."

Importantly, the syllabus is designed to keep the notoriously elusive attention of young men.

A lecture on the importance of strengthening the core to avoid injury, for instance, might not resonate with a young man who has never been hurt anyway. "But if we say that a stronger core is going to help your running times, going to give you extra distance on your kick, and for a ruckman stop you getting pushed off the ball so easily, then they listen," said McCartney.

Last year, the national under-18 championship was expanded from a one-week tournament to an eight-week series. This, said AFL development manager Kevin Sheehan, exposed draft prospects to a range of conditions, surfaces, opponents, and to the vagaries of playing home and away. It meant that AFL clubs could make better informed recruiting decisions.

"It's a great standard of footy now," said Sheehan. "It looks like an AFL game, the size, the pace, the tactics. Only the disposal skills are not quite as good." Instructively, the average height at last year's championship was 188 centimetres, also the average height of an AFL player. Some were as broad, too. These were juniors, but scarcely boys. Witness Rich.

Once drafted, a young footballer's development is more accelerated now than ever. Partly, this is because clubs at last have the players to themselves, without competition from school teams, or other sports. Partly, it is because of the sophistication of the clubs' programs, allowing each player to work on his own strengths and weaknesses. Partly, it is because the premium now is on skill and athleticism, not the darker arts.

And partly, crucially, it is because the system is unforgiving. Shorter lists mean that clubs turned over players more quickly, and so are more ruthless.

Young players, said McCartney, sensed the urgency. "With 38 players on the list, you've really only got two years," he said. "Years ago, with more players on the list, you had more time. Now, you need to make a mark early, or you're out the door. There's no 50-game VFL apprenticeships now."

In turn, this has changed the dynamics in the change rooms. "Once, when you were a younger player, you earned your stripes, you didn't say too much early on," McCartney said. "Now, the environment's different. They're actually encouraged to step up pretty quickly with regards to leadership. They're encouraged to speak up."

The sum of it all is the model, modern recruit, who is bigger, stronger and fitter than ever before, who is not overawed, who is tactically astute, whose skills have been honed, who is not blinded by the speed of the game, who can take refuge in the interchange bench when his legs begin to jelly, who is confident of the full protection of the law, whether his head is over the ball or 50 metres away — both dangerous places once — and who is hellbent on putting his stamp on the game.

So it was that Voss put first-gamer Aaron Cornelius on red-hot Justin Koschitzke last Sunday. It didn't work, but neither coach nor player was deterred. Voss remembered the attitude of his cleanskin, James Polkinghorne, after a thrashing at Geelong last month. "He was gutted, absolutely gutted," he said. "He's only played a few games of footy. When you see that as a coach, you know there's some character in those guys. They've taken some ownership of the team."