Numbers crunch salary cap's logic

In terms of defence, the top teams conceded only 42 per cent of all points scored before the cap was introduced, and 41 per cent following the cap. So there seems to be no evidence whatsoever that the salary cap narrowed the skewed distribution of skill across clubs.

An alternative test looks for evidence of less stability in the league ladder and more "churning". In other words, there should be a better chance that teams which finished in the bottom half of the ladder one year finished in the top half the next year.

Again, we found no improvement in the post-salary cap era.

In sum, it appears that the effect of the salary cap was precisely nothing. Unless you believe that the tournament would otherwise have become more lopsided during the 1990s, it is difficult to see that the salary cap made league any fairer at all.

In considering whether to keep the cap, we need to consider other factors as well. Some say that abolishing the salary cap could cause bidding wars to break out, placing a burden on financially strapped clubs. Yet this must be balanced with the fact that by increasing the fraction of league earnings that go back to the players, the game may also find itself better able to attract - and keep - sportsmen who would otherwise have gone elsewhere.

Importantly, whether the salary cap makes league more competitive is not merely a matter for the fans - it may also turn out to be of considerable interest to the courts.

The leading case on the legality of salary caps is the 1991 Federal Court decision of Adamson v NSWRL. Because the case centred around a challenge to the system of trading players, the plaintiffs agreed that they would not challenge the validity of the salary cap.

But the Federal Court did note in passing that a salary cap could only be legal if it could be shown that it was in the interests of the players and the general public. If not, it would be an unfair restraint of trade, and hence illegal.

Now that we have some evidence that rugby league did not become more competitive after the salary cap was introduced, would a court still hold that salary caps are in the public interest?