"Extreme Chess has most of the usual chess game features, but so do most other games. However there are two or three features that make it stand head and shoulders above every other chess game that I have seen. You can play black or white, choose among a half-dozen styles for the program to play in, or create your own style by adjusting how much emphasis the program should put on various pieces, or on attack and defence, or on the center and so on. You can study openings by having the program display all the possible moves that are in its opening book after each move in a window next to the board, and the moves are displayed in different colors to indicate best moves, "general" moves, gambits and moves that are not in the book. You can turn on the tutorial mode and adjust how much of a booboo you want to make before the tutor intervenes (the default is half a pawn: a screen will pop up telling you that this is not a very good move, with options to take the move back, to get a subtle hint or a broad hint.)

The program has most of the features that you can think of in a chess program, but the really good ones are the ones that I never thought of myself. One interesting feature is the ability to rate your play: you have to play a certain number of rated games, then the computer eventually will give you a rating. [Another] feature is the game's library of 50,000 games and its integration into the game. When you press the database button, you are taken to a screen from where you can load any of the available libraries, including some created by you, and one called Autosave where every game you play is saved. The available libraries include, beside the main 50,000-game humungus, libraries with games of historical interest, of Kasparov, Fischer and various other players. The main library has almost 200 games of Fischer and over 600 of Kasparov!

The game has outstanding analysis capabilities. You can tell the game to analyze any game that is on the screen or in the database. You can select any number of games and tell the computer to analyze them. You can select how much of a weakness requires comments by the computer, how long the computer should spend on each move and how many variations deep the computer should go. Even better is the game's ability to analyze a game in real-time, which makes this game indispensable to any but the very strongest serious chess players: select any move with the mouse and the board immediately displays the position on the board. If the "infinite analysis" is on, a window will display in real time the computer's ongoing analysis of the position as well as the depth (number of half-moves) it has reached, and an evaluation of how much the phasing player is ahead or behind. The tree-pruning algorithm is the best that I have seen: the analysis engine identifies the best move within ten seconds more than 90% of the time, and usually reaches 8-ply deep within a minute. Two or three minutes will usually allow the computer to reach ten half-moves deep, and it will very rarely fail to find the best move. The AI's ability to accurately and rapidly evaluate a position is indeed impressive. You can learn a lot about chess just by watching the computer analyze a game. Click on another move and the board will display the position and the computer will begin to analyze it immediately.

In summary, this is in my opinion one of the best chess programs around with features for players of every strength. Serious players will find the real-time and offline analysis capabilities of this game very useful, intermediate players will have fun playing with all the advanced features of the game, and beginners will find a useful teaching tool." Highly recommended for chess players at every skill level.