"With the vastly improved defensive skill of modern players, the tendency to not over-commit numbers to the breakdown and the reluctance of referees to regularly penalise offside offenders, there is often simply nowhere to go," wrote Slack in his column in the Courier Mail.
"The solution is to provide somewhere to go, courtesy of a deeper offside line at the scrum, ruck and maul.
"The law supposedly keeps defenders behind the rear foot of the last man at the scrum or breakdown, but even if it were stringently policed it leaves even the most potent attacker with little room in which to manoeuvre.
"Referees could catch infringing players almost non-stop but understandably are reluctant to keep blowing the whistle, so space is reduced even further for a large percentage of games.
"Whether the defenders should be moved back three, five or 10 metres is academic, and there is no doubt that whatever distance was legislated there would be players infringing."
Slack made it clear that for the rugby purist and for those of the forward persuasion that a battle between two packs also makes for an enthralling game, but said if rugby was to keep broadening its horizons by attracting new fans, then it had to be made more exciting.
"Players and spectators are screaming out for space and I fear for the game's popularity if law-makers are unable to refine the game's laws in ways that parallel the improvement of its players," said Slack.