Does a salary cap ensure a competition is more evenly balanced? That's the question raised by a recent study conducted by the players union into the last two seasons of the A-League that will be unveiled on Friday.

A comparison of the technical play of the A-League against the German Bundesliga, the J-League of Japan and North America's Major League Soccer reveals a limit on club expenditure does not necessarily guarantee a more competitive league.

Quality divide: There is a 33-point gap between Sydney FC at the top and the Reds at the bottom. Credit:Getty Images

The mid-season report conducted by Professional Footballers Australia suggests the gap between the strongest performers in the A-League and the challengers is significantly greater than that of the other three competitions, two of which have no salary cap in place. Japan and Germany operate without any restrictions on wages yet are more tightly contested. The MLS uses a similar salary cap to Australia yet remains the most competitive competition, suggesting player wage restrictions may not be the greatest influence on results. "Reports such as this provide the sport with an opportunity to benchmark the A-League against other leagues from around the world and to gain invaluable insight regarding the competition's international standing," PFA chief executive John Didulica said.

"The findings in relation to the competitiveness of the A-League, and as a result the efficacy of the salary cap, are interesting and we will continue to monitor this."