Until recently there has not been a commercially available neural network backgammon program. A neural network sets out to be a simulation of a biological brain, and neural net programs are developed by giving the program the basic rules of a situation and then letting it work out for itself the optimal strategy and tactics in any given position.

That situation changed earlier this year with the release of Jellyfish Tutor 1.0, which has taught itself to play backgammon by playing itself many thousands of times. Fredrik Dahl's creation is a breakthrough for the game of backgammon. Both its play of the pieces and its cube handling are at an expert level, making it a challenge for even the best players. Its developers claim that even expert players would find it difficult to score more than 55 per cent against it.

The human brain itself is vastly complex, with over ten trillion synapses connecting several billion neurons. The program cannot hope to emulate a human brain but in terms of size it can compare with lower organisms. Jellyfish, for example.

Running under Windows 3.1 (or later) Jellyfish is very user friendly in its presentation and operation and even those not familiar with computers would have no trouble in mastering its use. It also has an easy to understand manual. The program has some excellent features:

It plays both single games and matches; it has six different levels of play; it evaluates positions in terms of equity; it tells the player when he has made a cube error; it suggests a better move than the one played when appropriate. The last two features considerably enhance its value as a learning tool.

For the casual player, Jellyfish provides a strong opponent and a sure way to improve at a reasonable cost. The recently released "Analyser" version, which lets users roll out positions thousands of times to gain accurate understanding, will be an essential purchase for serious students. Those without it will be at a serious disadvantage on today's highly competitive circuit.

Full details of Jellyfish from: Effect Software, N0212 Oslo, Norway. Fax 004722-731155.