Match-fixing has also branched out from traditional hotbeds of corruption — Asia and the Balkans — to places like Canada, Finland and Norway, which rank among the least corrupt nations in the world. Until recently, no one — including sports regulators — thought to look for corruption in lower-level leagues. Still, given the vast amount of soccer betting, there's plenty of money to be made.
"It's liquidity of the markets," Forrest said. "You can make serious money only if you can put on (bet) serious money. In most sports, the bet you can make is too small."
Goalkeeper Richard Kingson of Ghana says he was offered — but declined — $300,000 to lose a game to the Czech Republic at the 2006 World Cup in Germany.
But prices have gone up. Italy's Calciopoli investigation found it cost up to $516,000 to fix a match in the top league of Serie A; $155,000 for a fix in the second division and $64,500 for a third-division fixed match.
In Croatia, court documents show that first-league games in 2010 could be fixed for as little as $25,600.
There is also a shift in the traditional match-fixing scenario in which players are paid to lose or referees are paid to make sure one team wins. With the rise of online spot betting — wagers made during the game — criminal gangs can predetermine not only the outcome of the match but also make money on bets like how many goals are scored, when they are scored, or who will take a penalty kick.
These live bets can "be particularly advantageous for criminals," according to Forrest's report, because they increase the number of wagers placed on the same fixed game.
As former Balkan warlords and Chinese businessmen have discovered, owning a club means players don't need to be paid extra to fix matches; they can just be ordered to lose. Corrupt team officials have also dangled career advancement instead of money before vulnerable young players.
"There is an increasing worry about gangs taking over football clubs as a way to further match-fixing ... and then they could also use the club to launder money," Forrest said. "It's quite cheap to buy a football club because so many of them are failing."
An American diplomatic cable released by WikiLeaks quoted the U.S. Embassy in Sofia as reporting that "Bulgarian soccer clubs are widely believed to be directly or indirectly controlled by organized crime figures who use their teams as a way to legitimize themselves, launder money and make a fast buck."
In 2011, Turkey's venerable Fenerbahce soccer club won 16 of its last 17 national league games to stay in the coveted Champions League — a benefit it estimated as worth $58.5 million a year. In July 2012, Fenerbahce President Aziz Yildirim was convicted of fixing four of those games and bribing to influence the outcome of three others. He did it by promising rival players a roster spot or arranging for referees who would favor his team.
Yildirim was one of 93 people who went on trial in Turkey last year for match-fixing — and only 14 of them were players.
Serbian player Boban Dmitrovic says he saw many instances in his home country where two clubs simply agreed on the outcome in advance.
"Right before the match, a note was handed to the players. They had to cooperate because their careers would be jeopardized," Dmitrovic told FIFPro, the soccer players' union.
This "chairman-to-chairman method" of match-fixing is still common in Russia, Albania and the Balkan nations, according to Forrest's sports corruption report.
The vast majority of the world's wagering originates in Asia, according to Forrest, but its own bettors shun that continent's games for those in Europe because Asian soccer has been so corrupt for years.
In 2011, China's main TV network refused to broadcast the country's soccer games because match-fixing was so widespread. Last year, two former heads of China's soccer federation were sentenced to 10½ years in prison.