Former Claret Joey Barton believes gambling is "culturally ingrained" in English football.
The 35-year-old one-cap England midfielder is currently serving a 13-month ban for breaking the Football Association's betting rules after admitting placing bets on 1,260 matches.
The FA tightened its regulations in 2014 to stop players in England's top eight divisions betting on any football-related activity, anywhere in the world.
Barton, who will be able to play again from June 1st, concedes he was right to be punished - but claims he is far from the only professional footballer to have been in clear breach of the FA's rules.
The former Manchester City man also insists the issue runs deep in English football.
"I think, and I'm being conservative, I think 50 per cent of the playing staff would be taken out (banned), because it's culturally ingrained," Barton told BBC Radio 4's Today programme.
"You'd have half the players out for sure."
He added: "I had to be sanctioned, because I stepped out of the boundaries of the rules. So there's no doubt about it, but the FA think I'm the only footballer who has ever bet on football ever
"But the reality of it says that that is not the case. I've seen (it) with my own eyes.
"I'd place bets for other footballers on my accounts. I would say, on a conservative estimate, being in professional dressing rooms where there's been readily available cash for over 15 years, you'd have half the league out."
Barton says the reason for that is because of the change in regulations.
He also believes it is important to distinguish between gambling rules and match-fixing rules.
He said: "The (gambling) rules have become more and more stringent. Ultimately we've ended up now with a totalitarian kind of ban - no football betting anywhere.
"Where we've got it wrong is we've got the gambling rules mixed up with the match-fixing rules.
"Because match-fixing is fundamentally wrong and challenges the integrity of the sport.
"I think culturally betting is acceptable. There's nothing wrong with betting if it's controlled - it's when it becomes out of control and people bet beyond their means."