Variations

 Best-of-n variant of match play

 From: Tim Chow Address: tchow@lsa.umich.edu Date: 8 February 2009 Subject: "Best of n" variant of match play Forum: rec.games.backgammon

```A nonstandard, but seemingly viable, way of running a match would be to
play (say) 25 games, with the winner being whoever is ahead at that point.
A single cubeless game could be played at the end to break ties if needed.

Does anybody (or did anybody, in the past) play this way?  If not, is there
any particular reason why not?  Has there been any theoretical analysis of
this variant, comparing it with standard match play and money play?

It seems to me that this variant of match play might be a decent model for
how a casual money player would want to play.  That is, imagine that I play
backgammon for money only once in a while, for an evening's entertainment.
My goal might be the maximize the probability that I'm ahead at the end of
the evening, rather than to maximize my expected winnings.  Although the
number of games is not rigidly fixed in this scenario, it's close enough
to being fixed to affect what "correct" play means, especially towards the
end of the evening.
--
Tim Chow       tchow-at-alum-dot-mit-dot-edu
```

 Neil Robins  writes: ```The real problem with this format would be that the match could, in reality, be over as early as the first game and the rest of the games would just be a trivial waste of time. For example, if in the first of 25 games I win 32 points there is no way you can win the match. I need never cube and can drop any and all cubes you give, and so your forced to try for undoubled gammons all the time, and when that fails you will already have a lost position in some games. ```

 Tim Chow  writes: ```It's true that since, in the format I suggest, there is no such thing as "clinching" the match, there is a risk that when someone pulls way ahead it will be impossible in practice to catch up, but since catching up is possible in theory, the games still have to be played out, which would be terribly boring. On the other hand, I'm not sure if this would really be a problem in practice. ```

 Walt  writes: ```My guess is that most matches would reach a point where the leader is n points ahead with n-1 games left to play, and that the typical value of n would be around 5. That leaves 5 or so boring exercises in gammon-avoidance to cap off each match. On the bright side, you might be able to market it as a cure for insomnia. ```

 Tim Chow  writes: ```How about this? The Jacoby rule isn't currently used in match play, but it could be reintroduced for my suggested variant. That should address this particular problem. A match would then be clinched when the lead exceeds the number of remaining games. ```

### Variations

Acey-deucy  (J. Nagel, Dec 2004)
Acey-deucy  (Steve Ewert, June 1998)
Acey-deucy  (Lee+, Jan 1997)
Acey-deucy  (John David Galt+, Dec 1995)
Acey-deucy  (James Eibisch, Apr 1995)
Backwards play  (Colin Bell+, Feb 1996)
Best-of-n variant of match play  (Tim Chow+, Feb 2009)
Bluff Cube  (Timothy Chow+, Dec 2012)
BluffGammon  (Christian Munk-Christensen, June 2009)
Cancelgammon  (Ilia Guzei+, Mar 2004)
Domino backgammon  (Laury Chizlett, Sept 1999)
Duodecagammon  (David Moeser, Dec 2000)
Duplicate backgammon  (Dean Gay+, Jan 1997)
Duplicate backgammon  (Albert Steg, Feb 1996)
Exact bearoff  (Chris Moellering+, Dec 2002)
Fevga  (George, Sept 2004)
Fevga (or Moultezim)  (Igor Sheyn+, May 1995)
Freeze-out match  (Dave Brotherton, July 1998)
Gabgammon  (jckz, Oct 2005)
Greek backgammon  (Alexandre Charitopoulos, Aug 2003)
Greek backgammon  (Alexandros Chatzipetros, June 1997)
Greek backgammon  (Marc Jacobs+, Feb 1994)
Hit man  (Matt Reklaitis, Jan 2004)
Hyper backgammon  (Gregg Cattanach+, Dec 2000)
Hyper backgammon  (Michael A Urban, Oct 1993)
International backgammon  (Bob Lancaster+, Oct 2002)
Jacquet  (Mark Driver, June 2001)
Joker cube  (Joe Russell+, May 2011)
Khachapuri  (Michael Petch+, Sept 2010)
Kleinman's tandem backgammon  (Fabrice Liardet+, May 2010)
LongRun  (Bill Hickey, Mar 2010)
Longgammon  (Michael Strato, Dec 2000)
Low number first, fixed dice, others.  (Walter Trice, Jan 1997)
Mexican  (Tom Henry, Apr 1997)
Middle Eastern backgammon  (Alan Cairns, Mar 2002)
Misere (backgammon to lose)  (Jason Lee+, July 2004)
Misere (backgammon to lose)  (Jason Lee+, Apr 1995)
Misere, Chase, Skewed dice  (Stein Kulseth, Jan 1997)
Nackgammon  (Ken Arnold, July 1996)
Nackgammon Shuffle  (Stick, Sept 2011)
Nackgammon opening moves  (Warwick+, Feb 2002)
Narde  (narde, Nov 2006)
Nardi  (KL Gerber+, Nov 2002)
No hit  (RedTop+, May 2004)
Nuclear backgammon  (Walt Swan, Apr 1997)
Old English  (Nick Wedd+, Feb 1996)
One roll lookahead  (Stephen Turner, Mar 1997)
Opening slot rule  (Gregg Cattanach, June 2006)
Other variations  (Douglas Zare, Feb 2000)
Plakoto  (Ed Dengler+, May 1995)
Plakoto  (Pasteel M., Feb 1994)
Plakoto express  (Athansios Vagias, Feb 2005)
Portes  (George, Sept 2004)
Roll-over  (Edward D. Collins, Oct 1997)
Russian backgammon  (Daavid Turnbull, Aug 1991)
SassanGammon  (Chiva Tafazzoli+, June 2009)
Shesh Besh  (G.S., May 2003)
Simborg Rule  (Scott+, Feb 2005)
Slot backgammon  (Fabrice Liardet+, Aug 2008)
Sudden death, Woodpecker, Gerhardsen  (Fredrik Dahl, Jan 1997)
Tablestakes betting  (TrueMoneygames, June 2002)
Takhteh  (Bruce Scott+, Mar 2003)
Tandem Backgammon  (Mislav Kovacic, Feb 2012)
Tavla  (Arda Findikoglu, Nov 2004)
Tavla  (ucc02cx+, Feb 1997)
Tavli (Portes, Plakoto, and Fevga)  (Jens Larsen, July 1997)
Tavli question  (Brus+, Apr 2011)
Tracy turn around  (Michael J. Zehr, Feb 1996)
Tri-gammon  (Gregg Cattanach, Sept 2000)
Trictrac  (David Levy+, May 1998)
Trigammon  (James Eibisch, Jan 1997)