shortest/longest games
Marc Gray
shortest backgammon game possible: "Alan Malcolm Beckerson (b. 21 Feb.
1938) devised a game of just 16 throws in 1982."
Does anyone know what the 16 shakes and their corresponding moves are?
Secondarily, I have long wondered how many moves were made in (my) longest
game. Last year I began keeping records.To date my longest game contains
143 shakes of the dice. The match appears below. It is perhaps worthy of
the upload because, not only is it lengthy, but it is a rather unusual
game to understate the case, and it contains an absurd take of a redouble
as well.
Score is 0-0 in a 5 point match.
moron is X - FlashGammon is O
O: (6 5) 24-18 18-13
X: (3 6) 12-18 12-15
O: (4 4) 13-9 9-5 13-9 9-5
X: (1 1) 17-18 19-20 19-20 1-2
O: (5 3) 8-3 6-3
X: (3 5) 12-17 15-18
O: (4 3) 6-2 24-21
X: (2 5) bar-2 2-7
O: (3 5) bar-22 6-1
X: (2 3) bar-2 18-21
O: (1 1) bar-24 22-21 3-2 3-2
X: (2 1) bar-1
O: (5 4) bar-21 13-8
X: (3 1) bar-1 7-10
O: (4 6) 13-7 8-4
X: (6 1) 1-7 17-18
O: (2 6) bar-23 13-7
X: (3 6) bar-3 1-7
O: (2 1) bar-23 8-7
X: (5 5) can't move
O: (5 2) 8-3 24-22
X: (3 2) bar-3
O: (5 5) can't move
X: (2 4) bar-4 18-20
O: (3 3) bar-22 bar-22 7-4 13-10
X: (6 1) bar-1
O: (4 4) 10-6 6-2 5-1 6-2
X: (1 4) bar-4 bar-1
O: (6 6) can't move
X: (4 1) 1-5 5-6
O: (6 1) bar-24
X: (5 1) 19-24 12-13
O: (3 6) bar-22
X: (6 6) 12-18 18-24 4-10 10-16
O: (2 2) bar-23 bar-23 bar-23 23-21
X: (2 6) 16-18 6-12
O: (5 3) 21-16 16-13
X: (4 2) bar-4 12-14
O: (6 6) 22-16 22-16 16-10 13-7
X: (1 4) 3-7 7-8
O: (1 3) bar-22 22-21
X: (3 6) 4-10 14-17
O: (6 1) can't move
X: (5 5) 8-13 13-18 10-15 15-20
O: (1 2) bar-23 23-22
X: (5 5) 19-24 19-24
O: (5 3) 22-19 21-16
X: (5 4) 20-24
O: (3 5) 16-11 16-13
X: (5 1) 18-19 19-24
O: (1 2) bar-23 23-22
X: (5 3) 17-20
O: (1 6) 22-21 13-7
X: (4 2) 18-20 20-24
O: (3 5) 21-16 16-13
X: (1 5) 18-19 19-24
O: (2 4) 22-18 23-21
X: (5 3) bar-5 5-8
O: (5 5) 13-8 23-18 21-16 16-11
X: (6 2) bar-6 6-8
O: (5 3) bar-22 11-6
X: (6 2) 8-14 14-16
O: (4 5) 21-16 11-7
X: (2 5) bar-5 17-19
O: (4 5) 23-19 22-17
X: (5 1) bar-1 bar-5
O: (5 4) 16-12 17-12
X: (5 5) 1-6 6-11 11-16 16-21
O: (2 3) bar-22 bar-23
X: (6 5) 5-11 11-16
O: (1 6) 22-21 22-16
X: (4 2) bar-4
O: (6 1) 12-6 7-6
X: (5 2) bar-5 5-7
O: (6 5) bar-19 12-7
X: (4 5) bar-5 4-8
O: (3 6) 16-13 19-13
X: (4 5) 8-12 12-17
O: (4 6) 23-17 18-14
X: (4 1) bar-4 4-5
O: (2 3) 19-17 17-14
X: (3 6) 5-11 5-8
O: (2 5) 13-11 13-8
X: (4 4) bar-4 bar-4 4-8 4-8
O: (5 6) bar-19 11-6
X: (4 2) 5-7 7-11
O: (1 5) can't move
X: (1 2) 20-21 21-23
O: (1 2) bar-23
X: (3 5) bar-5 5-8
O: (2 5) bar-23
X: (6 5) 11-17 8-13
O: (1 2) bar-23
X: (6 1) 17-18 13-19
O: (2 6) bar-19 bar-23
X: (1 5) bar-5 18-19
O: (2 4) bar-21 bar-23
X: (1 3) 5-8 19-20
O: (2 4) 23-21 23-19
X: (3 4) 8-12 12-15
O: (2 6) 23-21 21-15
X: (6 5) bar-5 5-11
O: (6 4) 15-11 11-5
X: (6 4) bar-4 4-10
O: (4 2) 14-10 19-17
X: (6 5) bar-5 8-14
O: (1 1) can't move
X: (6 4) 8-14 5-9
O: (4 6) bar-19 bar-21
X: (3 6) 14-17 9-15
O: (2 4) bar-21 19-17
X: (2 6) can't move
O: (5 5) 21-16 16-11 21-16 16-11
X: (1 5) bar-5 14-15
O: (5 1) 6-5 10-5
X: (4 3) bar-4 4-7
O: (6 6) 23-17 17-11 11-5 11-5
X: (3 3) 7-10 20-23 20-23 10-13
O: (3 4) bar-22 17-13
X: (3 6) bar-3 3-9
O: (5 1) 11-6 5-4
X: (4 3) 9-13 13-16
O: (3 1) bar-22 5-4
X: (6 4) 16-20
O: (1 4) 21-17 17-16
X: (3 1) 20-21 21-24
O: (4 2) bar-21 16-14
X: (5 4) 15-20 20-24
O: (5 5) 14-9 22-17 17-12 12-7
X: doubles
O: accepts
X: (6 4) 15-21 21-off
O: (6 3) bar-22 9-3
X: (1 6) 20-off 20-21
O: (2 3) 3-1 7-4
X: (2 5) 21-off 23-off
O: (3 5) 22-17 17-14
X: (5 6) 23-off 24-off
O: (6 2) 14-8 8-6
X: (4 1) 24-off 24-off
O: (4 1) 22-18 18-17
X: (1 2) 24-off 24-off
O: (5 5) 17-12 12-7 7-2 5-off
X: (6 6) 24-off 24-off 24-off 24-off
O: (4 5) 5-off 4-off
X: wins
--
no a me alienum puto
Kit Woolsey
: Marc Gray wrote:
: >
: > In the Guinness Book of World Records there appears the following re: the
: > shortest backgammon game possible: "Alan Malcolm Beckerson (b. 21 Feb.
: > 1938) devised a game of just 16 throws in 1982."
: > Does anyone know what the 16 shakes and their corresponding moves are?
: That's shortest game cubeless, of course. But I claim it's impossible. Each
: player starts with 34 tables to change, which can't be done in fewer than 9
: throws. So the shortest game most be at least 17 moves. I'll try and remember
: to ask Alan at the next BIBA tournament.
: No, I don't know what the moves were, but it's quite easy to devise some.
: What's not so easy is to devise a game where each player plays the correct
: moves all the time and it ends in 17 moves. Here is an attempt at such a game.
: I believe all the moves to be correct except X's 3rd move. (Though that's not
: so wrong that it's implausible that anyone might play it). Can anyone devise
: one were the indisputably right move is played all the time?
: Score is 0-0 in a 1 point match.
: Opponent is X - Turner is O
: O: (6 3) 24-18 13-10
: X: (3 5) 17-22 19-22
: O: (6 6) 24-18 13-7 13-7 10-4
: X: (5 5) 12-17 12-17 12-17 17-22
: O: (6 6) 13-7 13-7 8-2 8-2
: X: (5 5) 12-17 17-22 19-24 19-24
: O: (6 6) 18-12 18-12 12-6 8-2
: X: (2 3) bar-3 1-3
: O: (6 6) 7-1 7-1 7-1 7-1
: X: (3 3) bar-3 8-5 8-5 8-5
: O: (6 6) 12-6 6-off 6-off 6-off
: X: (2 3) 3-5 5-8
: O: (6 6) 6-off 6-off 6-off 6-off
: X: (6 5) 8-13 13-19
: O: (5 5) 4-off 2-off 2-off 2-off
: X: (4 3) 3-7 3-6
: O: (1 1) 1-off 1-off 1-off 1-off
Ok, Steve, I think I've found one (wasn't easy) which involves correct
play. All the moves were deemed correct by jellyfish level 5 (and only the
opening 4-3 play was close), so how bad can that be.
X: 4-3 13/10, 13/9
O: 5-5 13/3(2)
X: 5-5 13/3, 10/5, 8/3
O: 5-5 13/3, 13/8(2)
X: 6-6 24/18(2), 13/7(2)
O: 3-3 24/21(2), 8/5(2)
X: 6-6 18/12, 18/6, 9/3
O: 6-6 21/9(2)
After that, X just rolls 6-6 each roll.
I think this meets the stipulated conditions.
Kit
bobk
>In the Guinness Book of World Records there appears the following re: the
>shortest backgammon game possible: "Alan Malcolm Beckerson (b. 21 Feb.
>1938) devised a game of just 16 throws in 1982."
Almost all of us have done better. My record is one shake.
>Does anyone know what the 16 shakes and their corresponding moves are?
>
>Secondarily, I have long wondered how many moves were made in (my) longest
>game. Last year I began keeping records.To date my longest game contains
>143 shakes of the dice. The match appears below.
(match deleted)
I had a 200+ shake game on FIBS vs. tesauro (TDgammon).
Apparently it was too long for FIBS too save because I
got dropped twice when I tried to do oldmoves after the game.
Luckily Gerry Tesauro had it saved though. E-mail me if you would
like it.
Bob Koca
bobk on FIBS
Stephen Turner
>
> In the Guinness Book of World Records there appears the following re: the
> shortest backgammon game possible: "Alan Malcolm Beckerson (b. 21 Feb.
> 1938) devised a game of just 16 throws in 1982."
>
That's shortest game cubeless, of course. But I claim it's impossible. Each
--
Stephen R. E. Turner
Stochastic Networks Group, Statistical Laboratory, University of Cambridge
e-mail: sr...@cam.ac.uk WWW: http://www.statslab.cam.ac.uk/~sret1/home.html
Stephen Turner
>
> Marc Gray wrote:
> >
> > In the Guinness Book of World Records there appears the following re: the
> > shortest backgammon game possible: "Alan Malcolm Beckerson (b. 21 Feb.
> > 1938) devised a game of just 16 throws in 1982."
> > Does anyone know what the 16 shakes and their corresponding moves are?
> >
>
> That's shortest game cubeless, of course. But I claim it's impossible. Each
> player starts with 34 tables to change, which can't be done in fewer than 9
> throws. So the shortest game most be at least 17 moves. I'll try and remember
> to ask Alan at the next BIBA tournament.
>
Actually, it occurs to me that if the loser gets closed out, and doesn't roll
on those moves, one might do better than 17 THROWS, which was the original
question. I haven't been able to construct an example though, even one where
the players play bad moves. Can anyone provide an example or a proof of
impossiblity?
> Can anyone devise one (17 move game) were the indisputably right move is
> played all the time?
Well done Kit!
Michael Quinn
I don't think it can be done in 9 shakes. Consider the opening roll: this
cannot be a double, so 6-5 is the largest useful roll. If we're doing
sensible rolls, they can't all be 6-6, because you have 2 pieces blocked
by your opponents mid-point. This gives a game like:
X O
6,5 24-13 5,1 12-17 1-2
6-6 13-7 x2 8-2 x2 O dances until we don't care
6-6 7-1 x2 13-7 24-18
5-5 18-8 8-3 x2
6-6 13-7 x3 7-1
6-6 7-1 x3 6-o
6-6 6-o x4
6-6 3-o x2 2-o x2 (any double > 2)
That's 8 rolls and there are still 6 pieces on the 1-point. There are
only 2 rolls which lose a cross-over, the opening roll & 1 of the 5-5's.
These cross-over failures are inherent in the mid-point block, so unless
you concoct some variation which moves 4 pieces from 12-14, it cannot be
done in 17 throws.
mikeq.
--
Mike Quinn NEC Technologies (UK) Ltd. +44 (0)1734 654606
Midpoints come and go, but a five-prime is forever. Kit Woolsey, r.g.b