What do you think of this:
I saw this opening line in one of the games on the site. Is 4..Be7 really a great move that ruins white's plans to castle and attack black's kingside with eventual bishop sacrifice, or does white have an adequate response to it? What do you think?
It's, of course, not dead at non-master level, but as for master or grand-master level, wikipedia says it is almost not played since humble Bobby said he refuted the King's gambit (the Fisher defense). So has theory refuted it, wikipedia, again, says no, but why then is it not played much anymore?