In a game that is ever-changing, every action causes a reaction.

THE growth and development of football has never been faster. Not just outside the fence but inside. The game's ability to adapt and adjust to trends, rules and playing styles is unbelievable.

Just when we thought that tempo football and flooding were about to dominate into the future, along comes a new strategy to counter its limiting effects … interchange.

The increased number of rotations is not hindering football but helping it.

More interchange is a means by which football is combating the ugly tactic of flooding and is helping to make a quicker, more attractive style of game.

I'm a firm believer that for every action there will be a subsequent reaction and eventually football will find a workable balance. That's why we should always hasten slowly before we consider rule changes to counter one "trendy" strategy.

It's all part of football evolution.

The pace of the game has increased significantly since, in 2004, the rule-makers decided our game needed to change. That we had too much "dead" time and should see more ball in play.

They introduced three new rules: no holding the man up when on the mark; kicking the ball in straight after a behind; and changing the interpretation of holding the ball.

It has changed the game incredibly.

Some key statistics from Champion Data comparing the first three rounds of 2004 with the first three rounds of 2008 are interesting.

In 2004, there was a secondary ball-up ratio (where a ball-up failed to clear the area) of 23%. Last year, it was 20%.

In 2004, there was an average of 63 around-the-ground stoppages (ball-ups or throw-ins) a game. In the past three years, there have been fewer than 50.

About halfway through last year, I saw a significant change in the way the game was played. All of a sudden, teams that moved the ball slowly were being penalised because others had become so good at getting numbers behind the ball. If you moved the ball slowly, it was very hard to score.

So quick movement of the ball became a priority to beat numbers getting back, and an evolution of football, instigated by West Coast, was emerging: handball.

In 2004, the total handballs per team per game was 103. This year, it is 148.

In 2004, the average number of handballs received per team per game was 84. This year, it is 121.

In 2004, the kick-to-handball ratio was 1.83. This year, it is 1.36.

There's even been a significant jump in handballs and handballs received from this time 12 months ago, when the team averages were 136 and 113. And a significant drop in kick-to-handball ratio from 1.47.

What does all this mean? The ball is in play for longer. Players are running more and the game is quicker. Much quicker. The running is more intense and more relentless. And it's more about short, explosive bursts.

These rule and game-style changes now require fresh men on the ground at all times. The ability to get from one end of the ground to the other with power running is a prerequisite.

There is no place to hide in AFL football today if you can't run. And less time to rest on the ground.

A half-back flanker isn't a half-back flanker — he's a midfielder who starts outside the centre square. He's not a 13-beeper any more — he's a 15-beeper or he doesn't survive.

Collingwood was the architect of taking the interchange to a new level. I'm not sure if it was a personnel issue or a tactic but if there was a definitive moment it came in the elimination final last year against Sydney, which had become accustomed to dictating the one-on-one match-ups.

Mick Malthouse used 80-odd interchanges, an enormous number back then, to break the accountability of the Swans' midfielders and running players. He made it virtually impossible for them to know who was playing on whom. And it worked.

So, of course, we get more coaches using the interchange bench more often. And now 80-odd interchanges is the norm rather than the exception.

Still, despite all this, I'm not sure that having 100 interchanges gives you a greater chance than 80. That is certainly yet to be determined but in terms of the cosmetic look of our game, it has improved it dramatically.

Who cares if there are four or five changes at once? It's better than seeing a defender rack up 20 uncontested marks and seeing them chip the ball around to one another.

The only downside is that there are fewer one-on-one battles between one player and another.

There is still just as much contested football — it's just that more of it is at ground level.

No one is immune from the pine. Midfielders were normally the casualty but now it stretches across the ground. From full-forward to full-back.

That is an additional 12 players who need to be included at some stage in the rotation as part of the modern requirements of power running.

It has made the game more attractive and free-flowing. Surely that is not a bad thing. It has countered the most unattractive part of our game.

It does beg the question: Where does the game go next?

I can't wait to find out.