"Sacs" (No, Not the Quarterback!)

I personally think they're some of the most beautiful attacks in chess, but I don't understand them. I do understand that the position has to be JUST RIGHT in order for a sacrifice to happen--otherwise you lose a piece for nothing--but how on Earth do you sense/know it's the right time to commit present hara-kiri for future gain? 

Sacrifices: I DON'T GET 'EM!

You sense it through pattern recognition and know it through calculation :p.

Ah! I sensed a sacrifice in a chess tournament I was in, of the Bxh7+ variety. I knew the pattern was one I recognized, but I blew the moves that were supposed to follow the sacrifice. Instead I ended up trading a really good piece off stupidly.

Yes, just like JWestlake said, I sacrifice pieces through pattern recognition. I play turn-based games like I play standard-time games, and once I see that I have more pieces in the attack than you have in the defence, I sacrifice, without much calculation

Should you sacrifice when you're even point-wise? I have a friend who keeps telling me not to do that, and he's usually right. Still, others do it and succeed.

It doesn't really matter if we have an even amount of pieces. It's where the pieces are. If I have five pieces attacking your king, and you have three pieces immediately defending your king, then I'll probably sacrifice a piece to break up your pawn defense, knowing that two of your pieces are too far away to defend the attack.

Mating sacrifices? Hmmm--those never happen in my games, probably because I always go, "Now, why the !#$% would I throw my queen away like that???" Especially when I'm trying NOT to lose pieces and be behind. 

well you have to be high or you won't be able to see the sacrifices

Oh, good! I'll tell my nice friend Mary Jane to say hello, then. :P

Listen to these people here about sacs and you will be on your way to chess greatness!!  Good luck ladya79!

To illustrate a few keywords posted here such as "thematic", "pattern recognition" and / or "elimination of defenders", you can try to find commented versions of the games below. The sacrifices in these games illustrate the strength of the themes I have indicated. More or less, you recognize a theme or pattern that can provide you a strong initiative, thus you sacrifice material to enable it to express itself fully and be overwhelming.

Rook on the 7th rank

http://www.chessgames.com/perl/chessgame?gid=1032787

The B pair

http://www.chessgames.com/perl/chessgame?gid=1042533

The passed pawns

http://www.chessgames.com/perl/chessgame?gid=1090846

This was my 5 cents on the brilliant minds of masters. Have fun!

I love sacrificing pieces, it throws my opponent off balance.

Here's a game I just played where I sacrificed all my minor pieces. 

For a long time I also had to get over my irrational fear of parting with my pieces, but it pays off! 

http://www.chess.com/forum/view/game-showcase/3-sacrifices-1-game?lc=1#last_comment

Well i for one always look for remove the defender positions.

I'm confused by this.

That's pretty much how I sac even when it isn't a mating attack.  If they have pieces that will take time to get into the game, while mine are ready to go into action, then I'll sac either to create infiltration, or also just to remove their most active piece.

Did this Friday actually, exchange sac because his knight was his best piece, and all my remaining pieces were active while his rooks were out of the game... he thought it was a bit dubious at the time, but had to resign 5 moves later ;)

Tactical sacrifices are relatively easy, because you can calculate all of the key variations. I have little problem with this type of sacrifice.

Positional sacrifices where you can't see all the way to the point of material gain or checkmate are much more difficult, becuase you have to understand deeper concepts than just piece value. You're advantage, if it is there at all, is more abstract than "Mate in 3". I've only played this type sacrifice in a 'serious' game twice that I can remember. One was a GK game, and the other is a USCF CC game where I allowed the opponent to capture my rook with his bishop, which he didn't take. Here's the full GK game:

I had a decisive advantage at one point, but the game was extremely complex and I blundered it away. This sac actually wasn't too hard to make, because I quickly get two pawns for the piece and the compensation is obvious. I almost never make sacrifices like this unless I am fairly sure of them.

Here's a stupid sac that one of my opponents made. These are the kind of sacs that piss me off.

lol...well, I think you might have a bit of a tough time with some of Tal's. 

And I think the computer has a point about 10 Nxg5....I like it better than the rook check.

I remember calculating a lot of lines and I came to the conclusion that they were equal to eachother. I also remember directing the computer through the lines and it eventually came to the same conclusion. I could check again with my engine.

P.S. Tal was crazy. He didn't care if a sac is sound or not. Many of  his weren't really 'tactical' because they couldn't be calculated to the end. Tal's sacrifices belong in their own category I think, but I don't know what to call them.

The point is that if the queen is forced to leave d8 then the queen rook will hang to the Bxc6+ business.