Some negative aspects of chess softwares

In my previous articles "Computers, chess and A.I.", I have presented some dramatically positive aspects of the best chess softwares concerning a quasi human understanding of the chess positions. Today, on the contrary, I'm going to present some extremely negative aspects, especially concerning the defence of a position.

A "fortress" is a pieces' configuration against which the challenger is unable to do anything, despite a huge material superiority, and that involves a draw. I will present and comment three fortresses. A beginner, or a weak player, will easily understand all of them.

These three configurations have been analysed five hours long by the following strong chess softwares: Rybka (the best chess software existing that can be run on a PC), Fritz (which won a match by 6/4 against the world champion Valdimir Kramnik) and Hiarcs on a 3 GHz PC, with 1 GB of RAM. All the three softwares didn't stop going round in circles, giving a winning evaluation to the side which has the material superiority, without realizing that it was impossible to gain anything consistent. We can then make the statement that they didn't display any sign of "intelligence".

Fortress 1: White to move



It's one of the simplest known fortress: Whites, if they aren't in check, will move back-and-forth with their rook from f3 to h3; if they are in check, they will move the king, protecting the g3 pawn. Even a very weak chess player will understand this without difficulty.

We must notice that if this position is given to the Shredder chess software, it will immediately be recognized as a draw, because all the positions with a maximum of 6 pieces are recorded ("hard force").

Fortress 2: Black to move



This more complex fortress is composed exclusively by pawns. How could Black progress?

• The King has no entry into the white position;
• If they push forward their pawn a to a5 and then a4, White will answer by b4;
• If they push forward their pawn b to b4, White will answer by a4;
• As long as their rook stays on the h column, The white king will go back and forth between g1 and g2;
• If their rook goes to the f or g columns, the white king will go back and forth between f2 and g2;
• If their rook goes to the e column, the white king will go back and forth between f1 and f2;

No progression is possible, and the game will be a draw. While the position of the fortress 1 was quite simple and let us hope for an amelioration by the computer (without using "hard force"), the fortress 2 seems to be too difficult for any of such amelioration. Nevertheless even a weak player understands quite easily why the blacks can not do anything.

Fortress 3: Black to move



Here is another type of fortress. The black king has no available square and the h5 pawn is blocked by the king.

Black can only move with their queen: if she stays on the first line, between a1 and d1 or in f1, White answers g3 mate, winning the game; if they go on e1, the following move is also g3+, and if they go on g1 or h1, the white king captures the queen, and Black is stalemate (impossible to play a legal move, and the game is draw). If they leave the first line, for example if they take control of the diagonal b8-h2, White will operate back-and-forth with their king between g1 and h1. Once again, chess softwares persist in giving a noticeable advantage to the black position.

A possible improvement concerning these wrong evaluations could be the following: Add to the program a condition such as "if no improvement is reached after twenty moves - analyse deepness - or in other terms if the evaluation function, very positive in the beginning (due to the material difference), stays unchanged, then tackle in another way the position analyse.