Transfer rumours aren't an exact science.
If they were, Manchester United would have signed half the midfielders in the Europe by now, along with more than a dozen left-backs.
But while not every bit of speculation—or every player a club actively chases—ends in someone holding a scarf over their head on the pitch, it's a good guide to the strengths and weaknesses of a squad.
United don't have much of a midfield so are linked with a lot of midfielders. Patrice Evra is coming to the end of his career so David Moyes is said to be chasing a number of different left-backs.
But since Moyes took over in the summer, and especially during the January transfer window after a difficult start to the season, United haven't just been linked with midfielders and left-backs.
There have been centre-backs, wingers, strikers and even the odd goalkeeper. Right-footers, left-footers, defensive players and attacking ones.
Not all will join, not even one for each of those positions. But it tells a story about the perceived weakness of the squad. United are linked with players in every position because every position, it's believed, needs strengthening.
Moyes is also a factor.
He might have inherited a squad that won the Premier League title last season, but only Marouane Fellaini can claim to be the manager's choice (and even then the last-minute nature of the deal weakens the argument).
Rio Ferdinand, Rafael, Nemanja Vidic, Phil Jones and Jonny Evans are all proven winners, but they are Sir Alex Ferguson's players.
That's not to say Moyes doesn't rate them, but new managers have a natural instinct to bring in their own men.
It leads to speculation about positions in the squad that wouldn't have been mentioned if Ferguson was still in charge—he signed them so they get the benefit of the doubt.
Because every bit of transfer speculation doesn't materialise, it's easy to believe that journalists use a random story generator to manufacture stories. You get a player, a club and a price, and you've got your story.
But most rumours—at least those from credible sources—are based on something, whether it's a player or his agent briefing reporters or the club whispering about their interest.
And it says much about the job Moyes faces in the summer that United are at the centre of so much speculation.