A WEEK ago at the MCG, Collingwood defender Heath Shaw was tagged by West Coast's Adam Selwood. So we had the interesting situation in which a forward was sent out to nullify a defender.

Didn't happen in my day. Back then, it was always the backmen who were hell bent on closing down the forwards.

It was North Melbourne full-back David Dench who turned conventional thinking upside down. Dench was a dasher who was bold enough to leave his opponent and attack the footy.

Full-backs were not supposed to do that. For 100 years they played tight, had touch on their opponent and had their performance measured by how many possessions and goals their direct opponent gained.

My instructions in the 1968 grand final, when I played back-pocket for Carlton, were to punch the ball if it was in the air, and if you got it, to kick it out of bounds on the full. Dench in the '70s turned things around.

His dashing runs would include four or five bounces, and often would end with a goal from his own boot. All of a sudden, some backmen became attacking rebounders. Exciting stuff.

Now all teams are looking to have at least one attacking playmaker in the back half. Four of the best are Shaw, Adelaide's Andrew McLeod, Geelong's Matthew Scarlett and Port Adelaide's Peter Burgoyne.

All four finished top five in their club's best and fairest last year. In the '07 grand final, Scarlett at full-back had 29 disposals, the most for his team. It was an amazing performance that may well be never seen again.

So what are the qualities that these attacking defenders possess? All four are remarkable readers of the play. They sense where the ball is going much earlier than the average player. This is an innate skill.

Sure, experience can help, but basically you either have it or you don't. Shaw at just 22 is a young master at predicting what will unfold on the football field. All are great runners. They can blow up their opponents with gut-bursting searching long runs that can go the length of the ground.

Scarlett at full-back on bigger heavier opponents is exceptionally good at this. By stretching their opponents physically, they take the initiative away from the forward.

Because they are so fit and talented, their teammates readily give them the ball, thus all of them have high handball receive statistics. And when the ball is in their hands, they use it so efficiently. McLeod and Burgoyne are gifted kicks and rarely miss a target, Shaw is steadily improving while Scarlett has the confidence and composure to try at all times to bring the ball into the centre corridor.

So important have these players become to their teams, opposition coaches now try to limit their effect. So back to the MCG last week when Eagles coach John Worsfold tried to put the brakes on Shaw. Selwood is Worsfold's best player.

But instead of being assigned a Magpie midfielder, Selwood went forward to lure Shaw onto him, which he did. Selwood then tried to keep away from the ball, working on the theory that if he didn't get close to the leather, then Shaw wouldn't touch the ball either.

And it worked perfectly. Shaw averages 22 disposals a game. Against the Eagles he had only three kicks and four handballs. At every centre bounce, and there were 41 of them, Selwood would line up in the goal square, with Shaw at his side.

At boundary throw-ins in the Eagles' forward line, Selwood would not go to the stoppage. Instead he would push forward to a dangerous spot near the goals. Shaw felt obliged to go with him.

At half-time Shaw had touched the ball only once. During the half-time break I wondered if Collingwood coach Mick Malthouse would move Shaw to the midfield or give him another opponent.

He didn't. Why? Because it is a team game and with the Magpies dominating (they won by 100 points), why make moves just to build a player's possessions.

And it was also a chance to "rest" his star defender. Shaw would have covered half the ground he normally covers and have copped half the hits.

Two weeks ago against the Cats, Malthouse did his best to curtail Scarlett's dominance. It appeared Scarlett's opponent Anthony Rocca was under instructions to play high and wide, to push up towards the wings.

Scarlett followed because Rocca is a dangerous player. Magpie centre half-forward Travis Cloke then pushed back closer to goals to take Rocca's place. Playing on the inexperienced and undersized Harry Taylor, Cloke had a picnic, taking nine marks and kicking four goals.

The best way to counter the "star" defender being tagged, is to put the star defender onto a genuine star forward. If the tagger continues with his role, then the opposition theoretically has a man free and it's up to that team to use the free player to advantage.