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Win-Draw rates when playing with various modified Pawns: The Lieutenant Pawns, Moscovia Chess

Posted: Tue Dec 17, 2019 8:47 pm
by musketeerchess
When first thinking about changing the rules of Pawns, my main goal was to avoid the maximum number of positions that lead to draws due to some of the pawn weaknesses.
Sometimes adding additional rules doesn't lead to the results expected. In fact, when testing Moscovia Chess using the Lieutenant Pawns, the draw percentage remained high (over 50%) even if there was more than 44% won games with balanced statistics between white and black this wasn't the result i expected.

For reminder, Moscovia Pawns are as follows:
Lieutenant has the same rules than a Classic Pawn, difference is: it can make a backward one square non capturing move anywhere on the board except when at the initial square.
When reaching the 7th rank it has an additional one square non capturing sideways move, supposed to make the Pawn unstoppable and will Promote.

This trial is in the right direction. Further changes to the Lieutenant pawn seem necessary to have a more competitive game.
Lieutenant or Guardian to play Moscovia Chess.png
Lieutenant or Guardian to play Moscovia Chess.png (208.07 KiB) Viewed 523 times

Re: Win-Draw rates when playing with various modified Pawns: The Lieutenant Pawns, Moscovia Chess

Posted: Sun Dec 22, 2019 1:04 pm
by H.G.Muller
How do you mean, remained high? I usually see only about 32% drawing percentage in orthodox chess.

I am not sure that tinkering with the Pawns will achieve much in this respect anyway. The extra moves might help a bit for winning KP-K, but only a tiny fraction of chess games ends in KP-K.

It doesn't alter the fact that a difference of a Pawn is often not enough to win. In particular minor + Pawn vs minor is drawish because the defending minor can be sacrificed for the Pawn. Even the additional move(s) do not make the Pawn a match for the minor so that it can prevent that.

And making Pawn moves reversible makes it much more difficult to exert zugzwang. Which is the mechanism through which most Pawn endings are won. Allowing Pawns to retreat also makes it more difficult to sustain passers. (A Pawn on the file next to it could retreat to attack it again.) Or to avoid Pawn trading when ahead in piece material.

In addition, making the Pawn more mobile will make it more difficult to gain a Pawn in the first place.

Re: Win-Draw rates when playing with various modified Pawns: The Lieutenant Pawns, Moscovia Chess

Posted: Sun Dec 22, 2019 10:42 pm
by musketeerchess
Hi HG
Yes i meant that the additional rules for the Pawn gave a surprisingly still high percentage of draws.
i think that this is due to the fact that i use for my tests one single engine. This gives an idea concerning balance of the game, overall draw win percentage. I think that the best way to analyse this is to make tests with different engines. The variety in playing styles is helpful.

Re: Win-Draw rates when playing with various modified Pawns: The Lieutenant Pawns, Moscovia Chess

Posted: Mon Dec 23, 2019 9:16 am
by H.G.Muller
My experience is that it doesn't matter very much which engine you use, as long as you play it against itself. Because in that case any preference associated with style (e.g. like aggressively going for a King attack), and even plain misconceptions (wrong piece value that inverts the desirability of a certain trade) will be similarly evaluated by the opponent. Which will then try just as hard to prevent the style can be expressed (or the erroneous trade can be made) as the engine tries to express it, practically neutralizing the preference.