I was wondering what are the main ideas for white in the exchange variation, Ruy Lopez opening.
[fen "r1bqkbnr/1pp2ppp/p1p5/4p3/4P3/5N2/PPPP1PPP/RNBQK2R w KQkq - 0 5"]
Of course there are many ideas in this variation, but the single biggest one is to play d4 and trade the d-pawn for Black's e-pawn, then take advantage of the fact that it is much easier for you to make a passed pawn with your 4-to-3 advantage on the kingside than it is for Black to make a passed pawn with her 4-3 advantage on the queenside (because of her doubled pawns). If all the pieces get traded off and you end up in a pawn endgame, it is going to be very tough for Black. Naturally she will try not to let that happen.
The main idea, in the exchange variation of the Ruy is "exchange." White will play d4 next, followed by offering the exchange of queens in order to head for an early endgame. That's because he's traded away his light squared bishop, his best attacking piece.
The "classic game" for this opening was played in 1914 between world champion Emmanuel Lasker and future world champion J.R. Capablanca.
In "Chess Fundamentals," Capablanca noted that immediately after the queen exchange, "The reader should note that if all the pieces were exchanged, White would be practically a pawn ahead and therefore have a won game."
White relentlessly strove for the exchange of pieces in the game and won.