Imagine if in football it became a rule that Liverpool and Man United couldnt engage in transfer activity ?

Like Tottenham-Arsenal I can only see it happening for a player whose contract has run down. To attempt a big signing from the other is complimenting them in a way (i.e you have an excellent RB) and you know they're gonna refuse to avoid loss of face, so you dont attempt it. Might seem more likely to go for a squad player (like us with Silvestre) but then again squad players are not top quality so you can look elsewhere for that, I mean if Liverpool bought Darron Gibson would you really feel you had done United over? I suspect not.