# For All You Math-Lovers!

wittywonka
Posers and Puzzles 13 Feb '07 03:43
1. wittywonka
Chocolate Expert
13 Feb '07 03:43
How many possible moves (for white for ease sake) are there after:

0 random half-moves: 20
2 random half-moves:
4 random half-moves:
6 random half-moves:
8 random half-moves:
10 random half-moves:

For example, I think there are a total of 20 opening moves for white...as for the rest, I am both too lazy and mathematically challenged to solve...

Also...just a note...I have no idea to the answers, just curious...

Also...another curiousity...is there any sort of pattern of increase in number of moves?
2. 13 Feb '07 13:452 edits
http://www.research.att.com/~njas/sequences/A048987
http://www.research.att.com/~njas/sequences/A006494
http://www.research.att.com/~njas/sequences/A019319
http://www.research.att.com/~njas/sequences/A089957
http://www.research.att.com/~njas/sequences/A090051
http://www.research.att.com/~njas/sequences/A057745
http://www.research.att.com/~njas/sequences/A083276
3. XanthosNZ
Cancerous Bus Crash
13 Feb '07 14:27
Originally posted by David113
http://www.research.att.com/~njas/sequences/A048987
http://www.research.att.com/~njas/sequences/A006494
http://www.research.att.com/~njas/sequences/A019319
http://www.research.att.com/~njas/sequences/A089957
http://www.research.att.com/~njas/sequences/A090051
http://www.research.att.com/~njas/sequences/A057745
http://www.research.att.com/~njas/sequenc ...[text shortened]... n moves, including en passant and castling information, so why are the sequences not the same?)

A position is different depending on whether en passant is possible. However, the above position is the same whether or not the last move was ...f4 as even if en passant were possible it couldn't be played due to the pin according to one sequence and two different positions according to the other.
4. 14 Feb '07 02:27
Originally posted by XanthosNZ
[fen]rnbqkbnr/ppp3pp/8/3pPp2/5p2/8/PPPPQ1PP/RNB1KBNR w KQkq f6[/fen]

A position is different depending on whether en passant is possible. However, the above position is the same whether or not the last move was ...f4 as even if en passant were possible it couldn't be played due to the pin according to one sequence and two different positions according to the other.
ðŸ™‚
5. 14 Feb '07 10:07
Originally posted by XanthosNZ
due to the pin
what pin?
6. XanthosNZ
Cancerous Bus Crash
14 Feb '07 21:49
Originally posted by aging blitzer
what pin?
Hmmm is seems I messed up the example. Anyway, imagine the pawn that would take en passant is pinned to it's own king.
7. HandyAndy
Non sum qualis eram
14 Feb '07 22:13
Originally posted by XanthosNZ
Hmmm is seems I messed up the example. Anyway, imagine the pawn that would take en passant is pinned to it's own king.
its own king.