27 Aug '06 16:08>
Hi,
I have another question. It is a little bit long...
I once read that if after 50 moves without capture or pawn move the game ends, then the longest possible game is 5948.5 moves long. This is calculated as follows:
Maximal number of captures - 30
Maximal number of pawn moves - 96
At least 8 pawn moves must be captures, so we may think the maximal length is 50+50(96+30-8)=5950; but this answer assumes the first capture/pawn move is at half-move (= single move, ply) number 100, the second capture/pawn move is at half-move number 200, etc., which is impossible, since it assumes only black captures. Each time we swap from a sequence of captures/pawn moves every 50th move by one player to such a sequence by the other player we lose one tempo. WE MUST HAVE AT LEAST 3 SUCH SWAPS, so the correct answer is 5950-1.5=5948.5.
Now, finally, my question...
I understood all the above argument, exept the capitalized words. I don't understand why we must have 3 swaps from a sequence of captures/pawn moves every 50th move by one player to such a sequence by the other player. Why isn't one swap sufficient? and can somebody show how 3 swaps are sufficient? Thanks...
I have another question. It is a little bit long...
I once read that if after 50 moves without capture or pawn move the game ends, then the longest possible game is 5948.5 moves long. This is calculated as follows:
Maximal number of captures - 30
Maximal number of pawn moves - 96
At least 8 pawn moves must be captures, so we may think the maximal length is 50+50(96+30-8)=5950; but this answer assumes the first capture/pawn move is at half-move (= single move, ply) number 100, the second capture/pawn move is at half-move number 200, etc., which is impossible, since it assumes only black captures. Each time we swap from a sequence of captures/pawn moves every 50th move by one player to such a sequence by the other player we lose one tempo. WE MUST HAVE AT LEAST 3 SUCH SWAPS, so the correct answer is 5950-1.5=5948.5.
Now, finally, my question...
I understood all the above argument, exept the capitalized words. I don't understand why we must have 3 swaps from a sequence of captures/pawn moves every 50th move by one player to such a sequence by the other player. Why isn't one swap sufficient? and can somebody show how 3 swaps are sufficient? Thanks...