Accept the double is a blunder?

[puzzle_t0rico]

Hi there

In this game I was leading 1-0 to 3pt and White sent me the cube.



I accepted but after analysis by gnuBG it seems I made a big blunder (-0.329 of equity)



I do not really think so because I am winning this game 34% of the time and therefore, the match. In a money game is a clear take because the winning chances are more than 25%
In a match game like this, honnestly, for me, it is a clear take.
I am risking a 2-1 Crawford against a total victory the 34% of the time. Though maybe I am totally wrong and it would never be correct to take.
BTW, I took and I won the match 3-0
Please give me your advice.
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If the brain were simple enough to be understood, we would be too stupid to understand it.

[LuvChild]

Hi- I've only been playing for about 6 months now and just registered for this site but have completely fallen in love with the game. Hopefully my answer provides some clarity; though I'm sure some of the more experienced players might have a better/ different opinion:

I think the point you're missing on why this is a drop is the high percentage of gammons White gets in this match. It is, in fact, almost half their winning percentage. So, while you're encouraged by the fact that you win the match a third of the time and a third of the time you are 1-2 Crawford the final third of the time there's no third game because White will win 4 points from this position. My quick math (which is probably wrong- I'm doing this in my head as I type) tells me you have to be about 45% to win the game to take here. Being at 35% means a 10% equity loss- pretty significant.

And as a side note to everyone who posts in this forum please keep it coming- I've got about 30 years of learning ahead of me (and yes, I know probably forever actually) and know reading these posts has helped soften that learning curve already- so thank you!

[puzzle_t0rico]

This is an example to show that it is always good to ask for advice.
Indeed, the percentage of gammons is too high to take. You are true.
The probabilty of winning for me is 34% BUT in order to take we have to add half the percentage of gammons to the famous 25% in order to know if it is worth taking or not.
In this case, gnuBG considers that I shall lose 28.2% of the time by gammon (therefore the match) and this makes: 25+28.2/2 = 39.1%
So, my 34% is not enough to take. I took and I just was lucky to have good dice that let me win (or he had bad ones )
Thanks for your advice

See ya!!
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If the brain were simple enough to be understood, we would be too stupid to understand it.

[LuvChild]

No problem- glad to know I can be of help- and that I'm thinking correctly about this. Now, maybe you can help me:

The equation you run above for take percentage is one I'm familiar with, but I always thought the number added to the standard take point (25%) was not the percentage of games gammoned, but the percentage of your opponents wins gammoned. In that case the take would have been :

.25 + (.282/.66)/2 = .463, or 46% (close to my original guess of 45%)

I know I've seen Mr. Simborg post on this topic before but haven't found it yet in the forum library. I guess my question is- which is correct?

Thanks again!

[puzzle_t0rico]

Hi
Thanks for your analysis. I am not too strong in these calculations and winning estimations. I just try to feel if the position is favorable for me.

Though, there is an excellent article in this very site published around 3 weeks ago that talks about the Gammon factor and it is on there where I based my maths for this discussion.

There it is said:
"Is there a rule of thumb for these gammonish positions? Yes, there is:
Divide your expected gammon loss by 2 and add the figure to the ?normal? take percentage of 25%. Thus if you expect to lose a gammon 20% of the time (i.e. when you lose the game one fifth of those losses will be gammons) then add 10% to the 25% to give 35%. If you can win the game 35% of the time then you can take otherwise you must drop."

So, it is the opponent gammon winning chances that should be added.
Anyhow, these estimations are too strong for me and I can not even imagine how a human mind arrives to know more or less the gammon percentages.
_________________
If the brain were simple enough to be understood, we would be too stupid to understand it.