Elite Players Can't Get Out Off The Box

because it's silly to consider them just one opening. e4-e5; Nf3 is not just one opening. of course there is no objective criteria out there but few theorists would consider the QG just "one opening".

You can, because the implied point is that they can't break out of the habits (or trends) that they created themselves. Because they play a select amount of openings, rightly so, for that creates the best winning chances for them, they 'create' the box and then can't get out of it because it offers them the considerable weight of reliable theory.

That isn't to say that it doesn't make me sad (I'd like to see more Caro-Kanns, for example!), as I was a little depressed that not a single game of 1.e4 was played in the recent WC, but it's true that they stick to a certain standard set.

All i'm trying to say is that the box is simply the repertoire of the top players at the moment.  In ten years when there is most likely going to be a new batch of top players, they may have differnet repertoires then todays top players and then people can complain about that box.

I consider only top 20 players (and Judit Polgar) to elite players

according to the last three rounds because i got other things to do ,you know.

QG 7

RL 5

Queen's Indian 6

Sicilian 6

KID 4

4 knights 1

Nimzo Indian 4

Caro Kan 3

Petroff 2

French 1

English 1

Catalan 1

Scotch 1

13 openings, out of them 5 used only once, happy?

What do you mean by popular?

some assumptions

1) they all have a very high level of understanding

2) they all have excellent endgames , strategical understanding and tactical ability.

what are they trying to achieve?

1) White wants to gain an advantage and then have time to build or work with it. 

2) black wants to equalize. ie. gain equal chances 

3) complicated positions, either tactical or strategical. This is why you dont see a lot of exchange french openings where there are no real strategical or tactical complications and the tension just deflates into a draw. Sometime this is a desired result but not always.

4) play to your strengths and your opponents weaknesses: look at the recent Anand - Topalov match (or the famous Kasparov - Kramnik match) and you will see this in spades. This is one reason I do not see Topalov becoming WC (in the traditional , match, sense of the word) he is very frustrated by the openings where white gains a small advantage and he has to defend passively. Its not in his nature and he tries to lash out resulting in worsening the position for him. Topalov isnt flexible enough...

Also right now because computers allow someone to study deeply and prepare surprises it is dangerous for players at the top to play one opening for long. The trend now seems to be to be a moving target and play a variety of openings. Magnus once said that he didn't bother preparing for Ivanchuk because you don't know what he will play anyway, QGD, Nimzo, Dutch, e4 , d4, c4, he plays everything. Magnus is the same, you see him play something like the sicilian dragon but not for long stretches of time. Anand also... classic e4 player then suddenly switches to d4 as a main weapon. 

In the end it is irrelevent for 99% of chess players. Under 2400 everything is basically playable. There is an IM (2400) that plays, as black, 1 e4 e5 2. Nf3 Nf6 3. Nxe5 Nxe4?!! and draws against GMs. 

The Petrov/Petroff needs to be played more in my opinion we don't see it enough. Also a lot of other openings are played and if you will notice the GM's seem to be getting a bit more experimental (Recent rise in the Kings gambit,scotch game etc) Also when these guys are playing for 50k+ Euros one tends to use the strongest options available