Jermaine Jenas spoke on Match of the Day about Tottenham's coordinated pressing from the right angles. He emphasised that it had to be a collective thing, if one cog doesn't do it's job then the whole thing falls apart.
I recall an article from an ex Southampton player, Jack Cork I think it was who said Mauricio Pochettino would teach the players at what angle to have their feet when standing on the ground and exactly where to stand, moving players a foot to cut off different passing angles.
A pressing game incorporates that because the idea is to get the player in possession to pass the ball where you want him to pass it and that means eventually into a trap waiting to be sprung so we can pinch the ball back. A press can be reactive but it can also be proactive, forcing your opponent to dance to your tune.
Jenas pointed out that the angles Tottenham were pressing at was forcing Manchester City into corners to make mistakes. He made a very important point. I have spoken before that a player quite apart from knowing his own game must know the game of his teammates. Jenas noticed that no player was looking to see if their teammate was coming to press, they just expected it, they knew they would be there.
Everyone can't just run at the player with the ball, a shape and a defensive stability still has to be maintained which is why players have to hunt in packs. There is little point playing a pressing game on your own, at those times you play a covering role blocking off the passing routes that you can.
A press works when you have a trigger. All players don't just happen to decide to press together, again why you have to know each others game to know when they are instigating a press. Jenas pointed out Son was doing it a lot for Tottenham yesterday, he was the trigger.