"Intelligent" chess games analyzer

[bvk256]

I am one of the main developers of the Raptor chess interface for FICS (http://code.google.com/p/raptor-chess-interface) and recently I started to implement an automatic comments generator. It is supposed to analyze a game with an engine and provide some intelligent comments (much like Chessbase products do). Recently I stuck on the problem of implementing an automatic sacrifice recognition. Are there any algorithmic ideas how to do this? Or maybe some ideas on the comments generator?

[H.G.Muller]

Well, I guess a sacrifice is defined as a move that lowers the material evaluation at low search depth (e.g. Quiescence Search), while it increases the total score (possibly only at high depth). If you would gain the material back within a reasonable number of moves, (like in Queen's gambit), it would not be a true sacrifice.

[bvk256]

Currently the GUI uses only the information provided by an UCI engine (score, principal variation) and material counter. So this could be accomplished only by implementing a simple quiescence search on GUI's part?