MChess Pro: Challenging a Legend of Computer Chess

MChess Pro: Early Days

I first heard about the software program MChess Pro back around 1999, when reading a copy of “Australian Chess”, a great A4 sized chess magazine which is now sadly out of print.

Back then a chess-obsessed 16 year old with an attitude, I’d been digging around in the old storage cupboard at the Gosford Chess Club and found some ancient magazines covered in dust and asked the club director, Mike Roche (a scumbag who later embezzled the club’s money and skipped town) if I could “borrow” some of the magazines.

He agreed, and I was at least temporarily, the happiest chess nerd on the planet.

Within one issue from 1996 there was an article by International Master Guy West on his win in that year’s Australian Championships and I remember reading this article vividly.

West (who seems to be a talented writer as well) wrote about how he used the World Champion of software programs at that time, which was MChess Pro 6.0, during his preparation for the Championships.

What MChess Pro would have looked like back in 1995 Is MChess Pro Worth Using?

To chess players of today, MChess Pro 6.0 with its modest rating of 2435 is “weak” compared to today’s programs like Stockfish and co. with their ratings in the 3200 level stratosphere, but you have to remember that in 1996 MChess Pro was the WORLD CHAMPION of software programs.

At that time, to have a digital chess master able to study a position for hours while you sleep was a novelty especially since it wasn’t for a few more years that Kasparov was using Junior 6.0 regularly in opening preparation.

West wrote of how in his training with MChess Pro, how he’d get this sinking feeling when the computer’s evaluation changed sharply after a particular move and he’d realize that his move had been a mistake.

This developed into a kind of “sixth sense” wherein certain types of positions, he’d just “sense” that a move he’d made wasn’t right and would see in his mind’s eye, the computer evaluation jumping sharply…even without the computer being present!

So at that time, West was using a computer of roughly the same strength as himself for sparring, while his opponents were just playing by ear and perhaps getting some practice at the local chess club.

West could feed the computer openings that he knew his opponents would play and practice scenarios, whilst his opponents were just “analyzing” positions alone.

This is even before the age of the internet, so imagine not being able to play chess online or having access to all of the flood of resources we now have!

When he began his play in Championships he was prepared and confident, and still had this “sixth sense” working for him where he intuitively knew when his opponents had made a mistake based on his judgment of how the computer assessed similar positions (and of course being a strong master himself).

Not surprisingly, West won the Championships that year and marked his name in Australian Chess history.

I found that article fascinating and have remembered it to this day when my own rabid interest in computer chess is still burning strong.

The software’s wikipedia page gives the following information about MChess Pro:

MChess Pro is the name given to a chess playing computer program written by Martin Hirsch which won the World Microcomputer Chess Championship in 1995.

Playing style:

MChess Pro’s style of play is designed to be particularly human, and, more specifically, particularly positional.

MChess Pro uses ‘complex pattern recognition’, has an evaluation function designed to focus on positional factors, and uses aggressive variation pruning in its searches.

Playing strength:
MChess Pro was one of the strongest chess programs of the 1990s. MChess Pro finished 8th and was the highest placed computer in the 1991 AEGON Man-Machine tournament.

In the 10th AEGON event at the Hague in 1995, MChess Pro defeated three grandmasters and achieved a performance rating of 2652 Elo. MChess Pro has defeated a number of very strong players including Christiansen, Z. Polgar, Rohde, Shabalov, Cifuentes and Wolff.

By the end of the 1990s MChess Pro was slipping further down the SSDF (Swedish Chess Computer Association) rating lists and by 2001 was already outside the top 30 programs.

MChess Pro 8.0

This “style of play is designed to be particularly human” part grabbed my attention since I have been collecting chess software and engines whose style is more on the human side for training games and analysis.

Here is an example of its play from a 1995 game against GM Zsuzsa Polgar:

Not a bad game, right?

I also wanted to play long time control games against the computer and relay the moves to my nice wooden board, essentially treating it as a “real” game, as if I were against a real opponent.

When I play these training games, I want to feel as if I am across the board from a real live human opponent, and not get that sense of artificiality from the moves played against me.

So anyway, recently I dug up an archived copy of the final release of MChess Pro (version 8.0) and excitedly installed it using an MSDos emulator.

During a night when I had some spare time, I set up my beautiful pine chess board on my desk and made the mandatory coffee.

I came back with cup in hand and loaded up MChess Pro 8.0 and set it up to play a game against me at 60 minutes each for the whole game.

Its game time Mr Chess Pro…at long last!  🙂

Now guys… I have some rules I should mention for when playing computers that I use to ensure the games I play most closely simulate a normal human tournament game.

Rule 1: No view of the computer’s opening book (most computers make this visible, but I close the book window for training games)

Rule 2: No view of the computer’s evaluation, or thinking lines (for obvious reasons).

Rule 3: No takebacks

Rule 4: The same amount of thinking time on the clock.

The rules above, in my opinion, are excellent for assuring a great training environment, especially when used in sparring against a human-like computer opponent, so I sat down and made my first move, moving my queen’s pawn forward two squares before relaying the move to the computer screen.

How I went against my famous opponent (including the full game and analysis) is revealed in part two.