A couple of remarks about "focus" above brings other sports into mind as well. MANY baseball players have said they never hear the crowd when it counts. A guy is throwing a projectile at you at nearly 100 mph, you're not sure if it's going to be at your head or straight down the middle or outside. You have that .25 of a second to decide: where it is, when it will get there and if you should swing. If you thought about that guy in the stands calling your wife a lesbian or something, you better have a backup career. Playing a round of 'no-holds barred' golf with your buddies will cure you of that excuse of "that dog barked in my backswing... from that house across the lake". Our usual group of guys will generally keep talking to each other without deliberately trying to distract each other as they take a shot. We MIGHT keep quiet at times, others not so much. BUT- if we are one short and get hooked with a single, we keep our chatter to ourselves and clam up during their swings. If he catches on to our style, fine- if not, that's fine, too.
There was a great article on ESPN about this. Were baseball players talk about the sounds they like, dislike, being in the zone. A lot of them say its like the kevin kosner movie were he pitched a perfect game, were the crowd just fades away.
As for Sergio and the noise that is his problem, i get that, but still Tiger has to realize the presence he creates on the course. Just the fact he lied about the Marshall telling him Sergio was done hitting, shows that he knew he did something wrong and didn't want to admit to it. He doesn't like to show weakness of any form. Usually he's clean cut on the golf course, usually he doesn't answer questions were it would be damning to him. But this time he did, he lied, and it shows he knows he messed up. He didn't call Sergio's BS, he deflected. When you deflect, there's an underlying base of knowing you did something wrong. All he had to do was say, "I can't control what the crowd does", or "I didn't know the crowd would react that way to me choosing a club to hit. Next time i will be more aware." That would have been acceptable, and logically sound to basically mean Sergio needs to get a thicker skin, but he didn't do that. He deflected. I'm not saying Sergio is right, he has a clear problem with pressure, the crowd, Tiger's presence overall. But, Tiger also knows that in the game of golf, its a gentlemen's game. Jack Nicholas calmed a crowd for Tom Watson, Tiger woods deflected a remarks by lying about it.