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A foolproof guide to Isight?
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peps...@gmail.com
Apr 19, 2022, 6:04:30 AM4/19/22
to
I'm pleased that I finally got round to reading Axel's paper.
Despite my attempts to apply that method being wrong, I'm pretty
confident I can apply it in the future. But I have the advantage
of being incredibly good at mental arithmetic, so my case might
be atypical.
There are actually (at least) three Isight algos for money play.
1) Simple Isight without using delta _ l
2) The delta_l version
3) Using both but having an algo to determine whether you use
method 1 or method 2.
More correctly, 3) is a class of algos rather than a single algo.
Suppose we have a non-contact position and a player knows her mental
arithmetic ability. 100% means every computation is instant.
50% ability means that pip counts of approx 100 for each side takes
two minutes to evaluate.
Given the player's counting ability, it would be useful to have a clear algo.
Presumably a (theoretical) 100% player should always use the delta_l version?
For non-100% players, it would be useful (in my opinion) to flesh out
the algo for a range of mental arithmetic abilities.
For example, suppose the full 80 - l/3 + 2 * delta_l computation
takes 5 minutes?
It could also be useful to have simplifications such as: If you lead
by X pips and Y is true, it's D/P anyway.
Paul
Despite my attempts to apply that method being wrong, I'm pretty
confident I can apply it in the future. But I have the advantage
of being incredibly good at mental arithmetic, so my case might
be atypical.
There are actually (at least) three Isight algos for money play.
1) Simple Isight without using delta _ l
2) The delta_l version
3) Using both but having an algo to determine whether you use
method 1 or method 2.
More correctly, 3) is a class of algos rather than a single algo.
Suppose we have a non-contact position and a player knows her mental
arithmetic ability. 100% means every computation is instant.
50% ability means that pip counts of approx 100 for each side takes
two minutes to evaluate.
Given the player's counting ability, it would be useful to have a clear algo.
Presumably a (theoretical) 100% player should always use the delta_l version?
For non-100% players, it would be useful (in my opinion) to flesh out
the algo for a range of mental arithmetic abilities.
For example, suppose the full 80 - l/3 + 2 * delta_l computation
takes 5 minutes?
It could also be useful to have simplifications such as: If you lead
by X pips and Y is true, it's D/P anyway.
Paul
Axel Reichert
Apr 19, 2022, 7:10:15 AM4/19/22
to
"peps...@gmail.com" <peps...@gmail.com> writes:
> There are actually (at least) three Isight algos for money play.
> 1) Simple Isight without using delta _ l
> 2) The delta_l version
> 3) Using both but having an algo to determine whether you use
> method 1 or method 2.
1 and 2 give EXACTLY the same cube action in a money session. I prefer
> There are actually (at least) three Isight algos for money play.
> 1) Simple Isight without using delta _ l
> 2) The delta_l version
> 3) Using both but having an algo to determine whether you use
> method 1 or method 2.
the more general Delta l version, because it will give you a winning
percentage, which is required for match play. Then you "just" need to do
some match equity calculation to come up, say, with your cash point
(typically you want to double close to it) and act accordingly.
> It could also be useful to have simplifications such as: If you lead
> by X pips and Y is true, it's D/P anyway.
double if you have a smaller pipcount AND a smaller number of checkers
on board.
Best regards
Axel
peps...@gmail.com
Apr 19, 2022, 7:33:19 AM4/19/22
to
I'm going to try and be a bit sneaky and trip Isight up a little bit.
Let's make the position a bit atypical by giving the opponent just
a single checker on her 6 point. This maximises her recube vig.
I'll be on roll with two checkers on my two point.
This is well-known as redouble/take.
But, since the opp's recube vig is so high, she can take even though
her winning probability is small -- will this fool Isight?
I have a gap on my six point that she doesn't have.
So my count is 5. Hers is 6.
5 + 5/6 - 6 is negative so D/P which is wrong.
80 - 5/3 + 2 * 1 is bigger than 76 which is a wrong D/P as before.
Yes, the D/P is wrong. But maybe the probability is fine.
The probability of me winning if the game is played to the end
is 1 - (5/18 * 3/4) = 57/72 = 19/24 = 79%. 80 - 5/3 + 2 = 80 1/3 which ain't a bad approx.
I don't see the reason why the two algos would always give the same cube actions but I'll take your word for it.
Oh, ok. I think I get it. You start with an 80 year old man (call him Bob) and then assess how well he gets on
with his friends aged 68, 70 and 76. So there are differences involved and it probably translates to the 6, 5, 2 pattern when
you do the manipulations.
Paul
peps...@gmail.com
Apr 19, 2022, 7:41:21 AM4/19/22
to
Both our counts are in fact 6. 6 + 6/6 - 6 = 1. Still D/P.
How about the probability? 80 - 6/3 + 1 = 79%. Wow, that is pretty much perfection!
Paul
peps...@gmail.com
Apr 19, 2022, 7:43:18 AM4/19/22
to
Paul
Axel Reichert
Apr 19, 2022, 10:49:24 AM4/19/22
to
"peps...@gmail.com" <peps...@gmail.com> writes:
> I don't see the reason why the two algos would always give the same
> cube actions but I'll take your word for it.
This is by design. Explanation starting on page 24. Essentially Bower's
> I don't see the reason why the two algos would always give the same
> cube actions but I'll take your word for it.
interpolation generalized.
> Oh, ok. I think I get it. You start with an 80 year old man (call
> him Bob) and then assess how well he gets on with his friends aged 68,
> 70 and 76. So there are differences involved and it probably
> translates to the 6, 5, 2 pattern when you do the manipulations.
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