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Other than being a backgammon giant, Nack Ballard is famous for inventing Nackgammon, a variant that uses a slightly modified start position where both opponents have four checkers back instead of only two. But oddly he is much less famous for advocating Slot Backgammon, which from my short experience seems to be a far superior variant.
Slot Backgammon was introduced in a 2005 Gammonvillage article by Nack Ballard, where he acknowledges the idea as being Jake Jacobs', elaborating on an original idea by Phil Simborg. In Slot Backgammon, the start position is the usual Backgammon start position, but the player who wins the opening roll is forced to open the game with a slot, which here means leaving a blot (= a single checker) in direct range of the opponent's rear point (points 7 to 2). For instance, the best move with an opening 65 becomes 13/8 13/7 instead of running with 24/13 (which becomes illegal). Such a blot immediately makes the game hotter, since it induces either early hitting, either faster prime-building when the blot is missed and covered.
Just like in Nackgammon, the idea is to give rise to more interesting positions, but the playtesting I did seems to indicate that it does much better than Nackgammon in that respect. While Nackgammon most often results in a moderately complex double holding game, Slot Backgammon favours all of the most interesting types of positions. In comparison to usual backgammon, I have seen slightly more blitzes (virtually nonexistent in Nackgammon), many more priming games (I love those!), more backgames, less holding games and almost no races. Playing Slot Backgammon has been a thorough enjoyment sofar ; and I think it would be a great idea to use Slot Backgammon in top-notch tournaments, where games are likely to be played in front of thrilled onlookers, or even recorded and replayed by backgammon enthousiasts all over the world. But before that happens, all that the poor backgammon enthousiasts can see of Slot Backgammon is a stupid annotated match by me.
Two very minor further advantages of Slot Backgammon are that difficult decisions come earlier in the game - the non-hitting responses seem pretty difficult to me - and that the average equity after the first roll is very close to 0 - no advantage to playing first. The following table shows the best opening moves together with their equities, as by eXtremeGammon rollouts provided by Miran Tuhtan. I included the doubles, because with the first move being a disadvantage, allowing doubles for the opening rolls would mitigate that disadvantage, as seen below.
Roll | Slot | Equity | Weigth |
21 | 13/11 6/5 | 0,011 | 1 |
31 | 13/10 6/5 | -0,027 | 1 |
41 | 13/9 6/5 | -0,012 | 1 |
51 | 13/8 6/5 | -0,008 | 1 |
61 | 24/23 13/7 | -0,068 | 1 |
32 | 13/11 8/5 | -0,040 | 1 |
42 | 13/9 6/4 | -0,055 | 1 |
52 | 13/8 6/4 | -0,053 | 1 |
62 | 13/5 | -0,025 | 1 |
43 | 13/9 8/5 | -0,075 | 1 |
53 | 13/5 | -0,025 | 1 |
63 | 13/4 | -0,053 | 1 |
54 | 13/4 | -0,058 | 1 |
64 | 24/20 13/7 | -0,059 | 1 |
65 | 13/8 13/7 | -0,059 | 1 |
11 | 24/23 8/7 6/5(2) | 0,204 | 0,5 |
22 | 24/22 13/11(2) 6/4 | 0,070 | 0,5 |
33 | 13/10 8/5(2) 6/3 | 0,163 | 0,5 |
44 | 24/20(2) 13/5 | 0,261 | 0,5 |
55 | 13/8(2) 13/3 | -0,066 | 0,5 |
66 | 13/7(3) 8/2 | 0,164 | 0,5 |
Average without doubles | -0,040 | ||
Average with doubles | -0,012 |