tips on winning backgammons

[boop]

hi, in this crawford game, gnu's choice of taking 3 off and leaving a 61 51 danger next roll as opposed to my 6/1(3) 5/off leads me to believe that she's going for a backgammon. Am I correct? and if so do you think it was worth the risk, especially as I'm probably going to open the six point next move. Maybe it's because she's gained a roll with 3 off instead of 1.

This also reminds me of the situation where my opponent has removed a lot of pieces from the board before I hit and close my home board leading to the need to hold her on the bar, or in my home, for longer than normal.

So, any thoughts on winning either of these scenarios? I couldn't find useful search terms on google for "how to win a backgammon" which didn't produce results explaining how to save a gammon so I thought I'd ask here.

boop

[ah_clem]

Take a look at the little numbers below the heading.  For 6/1 6/off(3) they read:

0.945 0.893 0.067

and for the "safer" 6/1(3) 5/off we have

0.945 0.892 0.029


The first number is the winning percentage.  So you'll win 94.5% of games regardless of which play you make.  The second number is gammon percentage.  Again, it's about the same 89.2 or 89.3%.  The third number is the backgammon percentage, and there's a factor of two here - the bold play wins backgammon 6.7% of the time, while the "safe" play only wins a bg 2.9% of the time.

With these numbers at hand, it's clear that you have nothing to lose and much to gain by taking three off now instead of only taking one off.  Of course, figuring out these numbers over the board is not something that ordinary people can do.  The right play would not be obvious to me OTB.

So, yes, gnu is going for backgammon here, and yes it's worth the "additional risk" because it's no more risky - the additional bad rolls are compensated by having two additional checkers off.

[ah_clem]

This also reminds me of the situation where my opponent has removed a lot of pieces from the board before I hit and close my home board leading to the need to hold her on the bar, or in my home, for longer than normal.

So, any thoughts on winning either of these scenarios?

"Containment" is the concept.

http://www.bkgm.com/articles/GOL/Jul02/contain.htm

[boop]

ahhh ... thats what the strange numbers mean! 

and thanks for the link .. very interesting

boop

[dorbel]

At the end of the day, the figures show that it is the extra bgs that make the difference. How might you find the better play over the board? The first thing to note is that winning a gammon is almost worthless, getting you to dmp (50% MWC) whereas a plain win gets you to about 48.5%.
A backgammon though wins the match, so well worth a punt while White has a weak home board. Even if hit after your next turn, you will still be a favourite to enter and White will usually still have one or two checkers on the bar, so you can still win lots of games and backgammons even after being hit.
Would you take a bigger risk to go for the bg? Even if you take the White checkers from her midpoint and use them to close White's board, the aggressive 5/off(3) is still clearly correct!

[Zorba]

I would be curious to see what the best DMP play is, no (back-)gammon considerations, just pure winning chances.

6/1(3) 5/off may seem safer as it leaves no gap, but it's odd (five checkers) on the highest two points, which is not safe. And indeed, it leaves a blot next turn on 66, 55, 44, that's already 3 numbers. 33 leaves no shot right away, but a very unsafe position. Extra unsafety comes from ending up with clearing the fivepoint next turn, but having three checkers on the fourpoint (worst after f.i. after 65, 64 or 54 next turn), leading to quite a few blot leaving rolls.

So, the "safe"play just isn't that safe. A high gap is sometimes better than (or equal to) being odd on the highest two points, especially if you can take 2 extra checkers off right away. Not only for (back-)gammons, but also just for winning the game.

[boop]

Thanks guys .. I love this forum