Tackling. An essential part of soccer, of course, we all accept that. Well, just about. A year or two back, Michel Platini had the audacity to voice a notion that must have occurred to anyone who has watched more than one or two games: that the sport might be better off if tackling were banned.

The English, of course, threw a collective fit over such a heresy, and no more was heard of it. I am not about to revive that idea, but I do want to draw attention to the fact that tackling does cause a lot of problems, and that most of those problems arise because no one -- least of all the rule book -- has been able to give us a clear definition of what constitutes a legal tackle.

I shall take as the text for this sermon, a tackle made during the EPL game between Bolton Wanderers and Fulham last Saturday. We are at the 56th minute, Bolton its attacking: its South Korean midfielder Lee Chung-Yong dribbles the ball into the Fulham penalty area with Fulham’s Danny Murphy pursuing at his right shoulder. Murphy reaches forward with his right foot, and prods the ball forward as, more or less simultaneously, Lee goes down.

The referee allows play to continue, satisfied that there has been no foul. So, no penalty kick. As it happens, I think he got it wrong, but my point here is not the correctness or otherwise of the referee’s decision. It was a difficult call, and he called what he saw. Rather my point concerns the amount of physical contact surrounding Murphy’s challenge.

Murphy clearly did make contact with the ball, prodding it  forward, but only slightly -- indeed he immediately caught up with it, as Lee was going to ground. So one can safely assume that if Lee had not fallen, he would have got to the ball before Murphy.

So why did Lee fall?  Did he dive?  There was no caution from the referee, so evidently not. Which is where the replays explain matters. Lee fell because he was tripped by Murphy -- slightly before Murphy made contact with the ball. Just before Murphy’s right foot is moving forward to contact the ball, his left leg is making solid contact with Lee’s right leg, more than enough to break Lee’s running motion and to send him tumbling.

One might assume that to be a foul. One might be wrong. This is what the rule book says on the matter of contact when tackling: a direct free kick is awarded to the opposing team if a player “tackles an opponent to gain possession of the ball, making contact with the opponent before touching the ball.”

That’s clear enough, but there’s a major problem. That is what the rule book used to say. That wording was removed in 2008, without explanation.  The rule book no longer deals with this aspect of contact. There is only one conclusion to be drawn: that it is now acceptable to trip or otherwise flatten a player, as long as you then -- afterwards -- manage some sort of contact with the ball.

This is an extension of the more generally accepted view that it is OK for a tackler to bring down a player after he has made contact with the ball -- provided the referee doesn’t judge the tackle to be careless or reckless or to involve excessive force.

But that interpretation is, in my opinion, much too lenient on poor tackling. Returning to Murphy’s tackle. I’ll alter it slightly. Let’s say Murphy had touched the ball away, exactly as he did, but had made contact with Lee only after that. Most referees, I think would allow that. But should they? In this case, if Lee stays on his feet -- I should say if Lee is allowed (by Murphy) to stay on his feet -- he will retake possession of the ball and a dangerous Bolton attack will become more dangerous.

So we’re forced to acknowledge that a tackle can be judged successful not so much because the ball was won, but because the opponent was brought down. If the tackler -- provided he isn’t too vigorous -- is going to get the benefit of any doubt the referee may have, why shouldn’t the tackler aim to bring the player down before, during or after his tackle?

Of course, there is a complicating factor involved. The ball itself. If a tackler gets only ball, but in doing so forces the ball into his opponent so that the opponent trips over it, that is a fair tackle, without a doubt (assuming it is not done violently).

Tackling -- which will no doubt remain a crucial part of soccer -- is a an awkward activity for the rule makers who, as we’ve seen, have trouble defining what’s permissible and what isn’t.

But it also presents problems for the players. How does one learn to tackle? You can’t practice tackling on your own. You need a partner, or a victim, really. Do you know of any teams that have regular tackling drills? How would they be arranged? Who would be the players required to play the guinea pigs, suffering inexpert tackles and risking injury?

It doesn’t happen. Tackling is largely a self-taught skill, learned on the job. It seems likely that today’s game features more crude tackling than used to be the case, if only because modern tactics are so insistent on having everyone, including forwards, assume defensive duties.

Given that, the amount of crude tackling that is seen is hardly surprising. What does raise eyebrows, however, is that the rule book virtually encourages sloppy, even dangerous, tackling by ensuring that it can be judged as legitimate play.