The football rumour mill is a closed system. For it to start it needs to be agitated by some kind of event. If the rumour relates to a player, that event is either a bid from another club or a declaration from the player that he wants to move.
Rumours related to managers are almost exclusively triggered by another manager being fired. It is very rare that a manager steps down of their own accord. For obvious reasons, let’s focus on the manager related rumour mill.
Once the system is triggered, the press begin the process of speculating who might replace the fired manager. This is what keeps the journalists in a job, there’s no shame in it. With the internet; fan generated speculation is almost as instantaneous; albeit initially less realistic (for example, suggestions that Harry Redknapp might become the next Oxford manager).
Eventually, the crazier fan-driven ideas are reasoned out through the debate and the media and fan speculation settles to a few more realistic targets. This creates a domino effect throughout the game because by-and-large some of those targets already have jobs. For the clubs of potential targets the rumour mill begins to cycle around two questions; ‘will he go?’ and ‘who will replace him?’
The other factor at play is the bookmaker. They're often viewed as being the barometer of truth - 'the bookies favourite...' - that, however, is often misinterpreted as that they know what is actually going on. Their job is not to speculate, but to quantify the validity of any speculation. Their focus is on managing the odds to ensure they are long enough to attract punters' cash, short enough to protect them from taking a financial bath in the event of any payout. If they speculate (wildly proffer suggestions without evidence) then they add further uncertainty into the cycle, this increases the risk and reduces the likelihood of making money. They reflect speculation; they don’t generate it; so stories about shortening odds are simply re-hashes of old stories used to fill up air time.
Shortening odds are just a reflection of increased numbers of people putting money on a name in hope of a payout. The shorter the odds, the lower the payout – so if people flood to a particular name, the bookmaker moves quickly to reduce the size of the payout on that name. The reason people flood towards a particular name is because that name keeps coming up in the speculation. So, Chris Wilder’s odds are shortening because more people believe what they’re hearing. They believe what they’re hearing because they're hearing it so often. It’s like a Twitter trend; if a celebrity death trends on Twitter; eventually people believe the trend rather than the fact.
Neither club has said anything amongst all this; both sides will want to keep their powder dry in any current or future negotiation. If Oxford came out and said that it is true that Chris Wilder is likely to go to Coventry (after note: or Portsmouth or Northampton), then they effectively throw in their hand in the negotiation for compensation. If Coventry says they want Wilder, then his price goes up. As a result everyone keeps quiet whilst edging towards some sort of mutually agreed set of terms (if, of course, they are talking at all).
The only other factor here is outside agents; they may know something about any discussions that are going on between clubs. If the media spots a candidate at the ground of his pursuers, it is a pretty strong indication that something’s up. More covertly, agents of players and managers will facilitate movements by feeding information into the system.
It seems that most people know a bloke who knows a bloke who lives next door to the kit man who knows that Wilder is going. But, think about your boss or his boss’ boss; do you know if he’s applying for new job? I doubt it.
So, speculation and the recycling of speculation, appears to make up 90% of the source of any story. The emerging facts which tend make up the other 10% are not enough to fill up 24-hours of sports coverage on radio, TV, online and print. It helps to keep that in perspective when another retweet comes through about Wilder’s future.