Author: Vincent Diepeveen
Date: 07:27:33 09/18/03
Go up one level in this thread
On September 18, 2003 at 10:02:33, Edward Seid wrote: A very illusional game thanks to the rules. Trivially with the normal chess rules this is a much easier game to keep a draw than without :) If white goes e4, then black answers e5. If white goes a3 then black goes a6 in principle. In short the only option white has is to start with a pawn to the 3d rank one day. Instead very clever pruning methods involving a passer that's unstoppable and further than any pawn of the opponent, will reduce search space significantly. A good winning attempt for white is illustrated by a well known trick where 3 pawns at a4,b4,c4 win always from pawns at a6 b6 c6 as you can create a passer. So that is the only trick white can go for. Starting with for example 1.a4,a5 2.c3,c6 3.b4 now white can capture on a5 winning a move and after winning that move it can win another tempo by playing a6 bxa6 a5!, but black cannot play b5 creating symmetry. So i would go 3..b6 there Now c4 is never possible as you after axb4 can already evaluate that as a loss for white. b5 is never possible for white and bxa6 doesn't solve a thing forever. 4.d4 is answerred by d5. So playing for semi-symmetry for black is already very effective. So the first guess that this would be a simple draw for black is not exactly true, but at second glance a few simple rules will produce great killermoves for black. A good evaluation function and move ordering can do miracles in this game to find out it is a draw. >I'm learning how to program by reading Deitel's Visual Basic.NET How to Program. > I'm eager to try out my new skills on a chess-related project. > >The Pawn Game - as presented by GM Lev Alburt in Comprehensive Chess Course, Vol >1 > >[D]8/pppppppp/8/8/8/8/PPPPPPPP/8 w - - 0 0 > >The game is won by: >1- capturing all of the opponent's pawns >2- reaching the last rank first >3- 'stalemating' the opponent, while still having at least one move for yourself > >The game is drawn if: >1- both sides' pawns are blocked so that neither side can make any moves > >The programming exercise I've assigned to myself it to try to solve this game >using brute-force minimax. My question to you... can this game be solved on >today's typical desktop computer using brute-force? > >I've been thinking about this and have made the following observations: >1- while classical chess has a branching factor of around 30, the Pawn Game >branching factor is 16 in the initial position, and around 8 in the >'middlegame', and goes down with each capture. >2- the longest 'game' is certainly less than 81 ply, and is probably around >60-65 (81 ply is calculated by the impossible scenario of each side taking 40 >ply each to march all pawns to the 7th rank + 1 ply to promote) > >I'm not planning to use anything fancy like hashtables or board rotation. I'd >be happy if I'm successful in coding a 10x12 board representation (practice for >writing a classical chess engine in the future), a valid pawn move generator, >and a correct implementation of the minimax algorithm. > >I'm very curious what the solution to this game is. Is it a win/loss/draw for >White? Of the 16 possible White moves, which ones win/lose/draw? How long is >the longest game? How long is the shortest game? What is the distribution of >wins amongst the 3 methods of winning? > >Any thoughts or suggestions are appreciated.
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.