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While we're talking about analysing with a computer, I'd like to appeal to all UCI authors to implement "Next Best" and "Analyze Threat," which I believe are part of the UCI protocol. In ChessBase during infinite analysis, pressing the y-key should cause the engine (if it supports it) to analyse the second-best move, and pressing the x-key should cause the engine to show what move is best if it was the other side to move. Not all engines support either or both functions, but e.g. the latest Rybka and Hiarcs do - that's because I pestered their authors about it!

Marek Soszynski wrote:While we're talking about analysing with a computer, I'd like to appeal to all UCI authors to implement "Next Best" and "Analyze Threat," which I believe are part of the UCI protocol. In ChessBase during infinite analysis, pressing the y-key should cause the engine (if it supports it) to analyse the second-best move, and pressing the x-key should cause the engine to show what move is best if it was the other side to move. Not all engines support either or both functions, but e.g. the latest Rybka and Hiarcs do - that's because I pestered their authors about it!

Good job. Keep pestering!

Fritz can analyse an existing game or variation tree. By doing it backwards it may be able to keep some information in the transposition cache when moving to the previous move. But it needs the game/tree in advance.
Fritz has also an option to analyse a position. You have to specify how many moves it should find for the first, second, third and fourth halfmove. It just analyses the base position, then in a new step the first of the alternatives and so on. If my idea may be slow, this implementation on top of existing engines is very slow and I don't know in advance how many interesting alternatives exist on which level.