If there’s one thing football fans love discussing, it’s a good conspiracy theory. No matter how innocuous the event, no matter how inconsequential the outcome eventually proved, every self-respecting fan has at least one moment in the beautiful game that had, in his or her opinion, something darker lurking under the surface.

Here’s our top five.

Ronaldo and the World Cup Final ‘98

It’s 1998, and the biggest match in football is due to play host to two of the biggest stars on the planet.

On the French team is the mercurial Zinedine Zidane, one of the most elegant playmakers ever to grace the pitch. For Brazil, it’s Ronaldo, arguably the greatest striker of his generation and a global phenomenon equal to Pele.

However, throughout the match, which saw the French triumph 3-0, the two-time Ballon d’Or winner looked a shadow of his usual lethal self. Many theorised at the time that the occasion had merely got to him, but there has long been speculation that Ronaldo had suffered a seizure hours before the match and was in no fit state to play. However, Nike stepped in to demand that its star was featured on the biggest stage of all.

Bebe's Transfer to Manchester United

There has long been speculation surrounding Portuguese striker Bebe's transfer to Manchester United in 2010. Almost every aspect of the transfer has something fishy about it: the relatively high fee for an unknown and largely unproven player; the fact that Sir Alex Ferguson had apparently never seen him in the flesh before forking out £7.4 million for his signature; and his subsequent failure to make any significant inroads at United or any of the teams he's been loaned to.

Most theories have centred around possible illegitimate payments to agents and representatives, particularly when it became apparent that Bebe's agent Jorge Mendes is also the agent of former United assistant manager Carlos Queiroz.

However, there's one that stands out from the rest. As the story goes, Red Devils player Nani had accidentally taken a performance-enhancing drug prior to a doping test while on national duty with Portugal, who were managed by Queiroz at the time. He was then sent home with a mysterious shoulder injury just hours before he would have been required to take the test.

The theory is that Ferguson requested Queiroz to excuse Nani and help disrupt the drug test–something which Queiroz has subsequently been found guilty of and which contributed to his sacking from the post–and in exchange paid a vastly inflated sum for Bebe in order to give Mendes and Queiroz both a sizeable payoff as a thank you.

South Korea at the 2002 World Cup

Everybody loves a good run by a host nation in a major international tournament, particularly when that host nation–as was the case with South Korea in 2002–is a bit of an underdog. South Korea made it all the way to the semi-finals that year, a feat not beyond the realm of possibility given home advantage and the failure of many major nations (such as Portugal and France) to make it beyond the group stages.

However, two matches in the South Koreans' run to the penultimate round of the tournament stuck out as having something slightly amiss about them. The first knockout round saw them triumph over Italy after extra time. The 90 minutes went by without much incident and the scores locked at 1-1, but Francesco Totti was then sent off harshly after the referee judged he’d dived.

To make matters worse, Damiano Tommassi then had a goal incorrectly ruled out for offside, which would have seen the Italians through due to the golden goal rule still being in effect at the time. The South Koreans then knocked them out with a golden goal of their own.

The referee for the match, Byron Moreno, served multiple suspensions throughout his career for questionable decisions, and most recently spent time in prison for smuggling heroin.

However, that paled in comparison to the South Koreans' next match against Spain. The Spanish should have won it in normal time when an own goal was inexplicably ruled out. Once again, controversy surfaced in the golden goal situation, where Spain had another goal chalked off for crossing the byline when it was clearly still in play.

Following the quarter-final, one Korean newspaper warned their run was “no longer a miracle,” which speaks volumes.

Image Laundering

Less of a conspiracy theory and more of an interpretation, many have suggested that several high-profile club owners and sponsors–such as Roman Abramovich of Chelsea, Sheikh Mansour of Manchester City and Qatar Airways’ sponsorship of Barcelona–are ways of regimes with questionable histories and practices to essentially launder their images in the West.

For example, Man City chairman Khaldoon Al Mubarak has said that Abu Dhabi’s ownership of the club is “showing the world the true essence of who Abu Dhabi is and what Abu Dhabi is about.” However, many have been quick to point out that the state has a string of questionable human rights charges to its name and would presumably much prefer their on-field successes taking precedence over their own domestic issues in the eyes of the West.

Russia and Qatar Hosting the 2018 and 2022 World Cups

You get the impression that it’s only a matter of time before this goes from being a theory to empirical fact. Everything about the process which granted the 2018 and 2022 World Cups to Russia and Qatar seems suspicious. The voting process revealed that in both cases countries were apparently voted for in order to knock more favoured nations out before the votes switched in later rounds.

Allegations of bribery are rife, with former FIFA vice president Jack Warner alleged to have received $2 million in payments from a firm linked to the successful Qatari bid. FIFA’s subsequent internal investigations into possible corruption have been branded completely impotent.