Some stay just this side of legality. Some drive a coach and horses through the regulations.

Some might stay within the letter of the law, some might show scant disregard for the ethics of their rules and their competition's integrity and take the risk that they won't get found out.

After all, in the highly competitive world of professional sport, where soccer clubs, AFL teams, rugby clubs and NRL franchises are all scrambling not just for the fan dollar but support from a limited number of sponsors and corporate backers, success at any price is far too often the driving motivation. Winners are grinners, the saying goes, and runner up is merely the first loser.

We saw it with Carlton in the AFL some years ago when the Blues cheated on the salary cap and were eventually sprung, being fined heavily and deprived of precious early draft picks for a couple of seasons as a punishment. It might be said that the current  woes at Princes Park are in some ways attributable to those crimes and that punishment.

Melbourne Storm in the NRL are probably the most blatant examples of salary cap cheats when the champion club was found to have systemically rorted the cap. It paid a heavy price, its name besmirched and its championships stripped from the record books.

The A-League examples, while perhaps not as egregious as those of the Storm, are nonetheless a blight on its reputation as well.

In the first season, Sydney — the team owned in part by the FFA's billionaire chaiman Frank Lowy — was found to have overspent  on the salary cap. Its "crime" was discovered after it had won the first ever A-League grand final, and the board and management decided to let it keep its title and offer what really amounted to a slap on the wrist as punishment, the loss of three competition points and a fine.

Perth Glory's offence this season is of an altogether more spectacular nature.

It was found — after Fairfax Media broke the story — to have cheated on the A-League's $2.55 million salary cap to the tune of hundreds of thousands of dollars. Punishment was swift and harsh: David Gallop, the FFA CEO (and the man who handed down the swingeing penalties on the Storm in his previous role as CEO of the NRL) announced earlier this month that Glory would be excluded from the finals and fined $269,000.

The "offences" committed by Victory in the loan deals that my Fairfax Media colleague Mark Hawthorne reveals this weekend are nowhere near as serious in scale, but in principle all salary cap infractions can be seen as hitting at the integrity of the competition and its equalisation policy. In the end the FFA decided not to charge Victory with any breach, but the fact that it shortly afterwards amended the regulation showed how close Victory was sailing to the wind. Some will argue that it was merely smart exploitation of the existing regulations, others would say that it might have been within the letter of the law, but without the spirit.

At the time when Tom Rogic arrived in Melbourne on a loan deal from Celtic, it was widely known that he had been acting on the advice of former Victory coach Ange Postecoglou, who had just taken over as national team coach.

The new Socceroo boss regarded Rogic as a major talent and had pencilled him in to be a key player in his squad for the World Cup in Brazil in June 2014. But Postecoglou has a strict policy for selection: he wants his Socceroo representatives to be playing first team football.

Rogic wasn't getting it at Celtic, so the loan move to Victory seemed a perfect solution to ensure a player of his quality would play regularly and be in top shape to go to the World Cup.

It didn't work out like that. Rogic barely played for Victory as he succumbed to the series of injuries that have regularly dogged his short career.

Postecoglou took him to Brazil but decided at the last moment not to include him in his 23-man squad for the tournament proper as he could not guarantee his match fitness.

James Troisi, who had joined Victory at the start of the 2013-14 A-League season, was a different case, at least on the pitch. The attacking midfielder played for the navy blues throughout the season and became one of the A-League's best. He had moved back to Australia from Italy, where he wasn't playing regularly, precisely because he wanted to impress Postecoglou before the World Cup.

His form for Victory ensured him a call up to the World Cup squad: he played in matches there and parlayed his form in the tournament into a move back to Europe, where he currently plays in the Belgian top division. He scored Australia's crucial second goal in the recent 2-2 draw with Germany.