I remember seeing an opening where a queen sacrifice was part of normal book/theory. I remember Anand playing it once during blindfold chess. Does anyone know that opening system and the name?

Thanks.

No clue... could you at least tell us was it with white pieces?  e4 d4?  It was probrably a line in an opening.

I think it was with the white pieces. Can't remember if it was e4 or d4 or something. It was definitely a line in an opening but it is certainly one I have probably never encountered and very unfamiliar with.

It's a sicilian najdorf variation, as far as I can remember, and it envolves sacrificing the queen for thee minor pieces. I don't remember for sure how many minor pieces and which ones they were. All I know is that it was a sicilian najdorf, on the white side.

Hmm...Okay, thank you.

I think you may be asking about this game : http://www.chessgames.com/perl/chessgame?gid=1043999

Its a sicilian najdorf and the queen sac is known theory now, I dont know if it was before this game however ?

Another known queen sacrifice in opening theory is this one :

That looks about right...

Another theoretical queen sac:

There's another one in the KID

You could try searching game databases for Arnand's games.  Was it a trap ending in a quick mate?  In which case there are thousands.  Blindfold games are usually played against beginners, so it could easily be such.  If by "book" you mean sound, correct play by both players, you have reduced the number enourmously, but there may be some "not played much since the 19th century" possibilities. 

Are you thinking of Legal's mate perhaps?

It wasn't Legal's mate, the game was actually against another fellow GM in a tournament where it featured Blindfold and Blitz games. Perhaps somebody can remind me of that tournament? I forgot the name of the tourney...

That tournament must be the yearly Melody Amber tournament.

it is legal mate