04-02-2013, 11:15 PM
Donald,
We're discussing an artificial position - not a normal game. If Knights cannot move, how do you think they all disappeared from the board? Obviously, they were captured on their original squares. Now, let's just take the WN on g1. It can only have been captured by a Black piece moving on Black squares. That restricts the choice to BQ, BB (f8) or BR (h8). Moreover, the WR (h1) would not have been able to recapture on g1 (wrong colour of square). Furthermore, if the capture on g1 were effected by the BQ or BR (h8), the WB (f1) would either have had to be on f1 or available to intervene on f1 - to avoid check forcing the WK to move away from e1.
So, you can see very readily that it would be impossible to reconstruct every move of the game - known as a proof game.
All we can do is meet the requirements of the position and conditions that Keith imposed. The moves leading up to that position - especially the earlier ones that led to mass exchanges and consequent simplification - have to be legal, not rational or optimal.
We're discussing an artificial position - not a normal game. If Knights cannot move, how do you think they all disappeared from the board? Obviously, they were captured on their original squares. Now, let's just take the WN on g1. It can only have been captured by a Black piece moving on Black squares. That restricts the choice to BQ, BB (f8) or BR (h8). Moreover, the WR (h1) would not have been able to recapture on g1 (wrong colour of square). Furthermore, if the capture on g1 were effected by the BQ or BR (h8), the WB (f1) would either have had to be on f1 or available to intervene on f1 - to avoid check forcing the WK to move away from e1.
So, you can see very readily that it would be impossible to reconstruct every move of the game - known as a proof game.
All we can do is meet the requirements of the position and conditions that Keith imposed. The moves leading up to that position - especially the earlier ones that led to mass exchanges and consequent simplification - have to be legal, not rational or optimal.