On the "Planet of PRs", why would any ape make "PR sacrificing moves for tactical reasons"?

Warning! This is a trap question. Don't try to answer. ;)

MK

On Wednesday, October 13, 2021 at 9:26:49 AM UTC+1, MK wrote:
> On the "Planet of PRs", why would any ape make "PR sacrificing moves for tactical reasons"?
>
> Warning! This is a trap question. Don't try to answer. ;)
>
> MK

That's when a player (like Tim for example) says (to himself) "I don't actually think it's good enough to
double but I'll double anyway because I've seen that my opponent (for example, Jim Plaskett) often
passes this type of position." It's a good tactical double but it sacrifices PR.

Paul

On October 13, 2021 at 6:43:13 AM UTC-6, peps...@gmail.com wrote:

> On Wednesday, October 13, 2021 at 9:26:49 AM UTC+1, MK wrote:

>> On the "Planet of PRs", why would any ape make "PR sacrificing moves for tactical reasons"?
>> Warning! This is a trap question. Don't try to answer. ;)
> That's when a player (like Tim for example)

I didn't say "chimps". I said "apes". In fact, the bigger the better apes,
like Gigantopithecus for example, if not Mr King Kong himself. I bet
this guy had a PR that you couldn't shake a "stick" at. :)

https://www.nationalgeographic.com/science/article/160106-science-evolution-apes-giant

Seriously though, your courage and willingness to give an answer,
despite my warning, deserves respect and a reply as well.

Does Tim know how to play backgammon? For being one of his last
fans, you must think so but what is his PR to be worth talking about
in terms of "sacrificing"?

> says (to himself) "I don't actually think it's good enough to
> double but I'll double anyway because I've seen that my opponent
> (for example, Jim Plaskett) often passes this type of position."

1- You need to provide an "actual example" of this having happened
between Tim and Jim (or John, or Jack). Can you?

2- Tim's doing that would be taking a calculated risk in order to gain
more. "Often" is not a statistically acceptable term. But still, can you
at least give some number of examples where Tim doubled not good
enough and also Jim passed? I will even accept examples of Tim and
Jim making these decisions not necessarily against each other but
also each doing these separately against their other opponents.

3- Can you show that sacrificing PR paid off for Tim "often enough"?
Surely, he is not so stupid to keep doing it and losing more as a result.

4- Can you show that Jim's passing wrongly is not also a tactical PR
sacrificing move? What happens when he does that? Does he win or
lose "more often"?

5- I recognize the difficulty of showing statistically sufficient examples
of this or a similar tactical moves made by human in a life span. Thus,
I will accept as an alternative proof of his ability to make such moves
knowingly. In other words, Tim's "saying to himself" is not good enough.
He needs to demonstrate that he can "say it outloud" before he makes
move. In fact, I'm in sucha good mood that I won't even require him to
know the exact PR difference sacrificed. It will be good enough if he
says that there is better move than what he will be making.

6- PR means "not taking chances", "not gambling" but doing the right,
best move. Bots never gamble. Especially in a short run, like a human
life span. If Tim and Jim can only play a few matches in their lifetimes
and if the occurrence of the above example events is even rarer, then
it is plain irrational to wrongly double "thinking" that the opponent will
wrongly pass. What if Jim will wrongly pass as in the example 100
"often times out of 150 total" in his lifetime but doesn't do it in the only
5 times it comes up playing against Tim?

7- Interestingly your example is about "cube skill", "doubling window"
which is too vague based on too wide an approximate calculation.

8- Pfew! Okay, I'll stop here. :)

> It's a good tactical double but it sacrifices PR.

All of you bott kissers need to frame this gem and hang it on your wall.

"Tactical" moves imply "strategy". And that, meaning not just a single
bullshit called "bot strategy", "optimum strategy", "equilibrium strategy",
"solved strategy", etc. but meaning "strategies" in plural...

I'm elated to see that some of you flock are starting come around on
this subject... ;)

MK

On 2021-10-13, MK <murat@compuplus.net> wrote:

> On the "Planet of PRs", why would any ape make "PR sacrificing moves
> for tactical reasons"?

Because in some circumstances it's the right thing to do. Why else ?

An example that Stick casually mentionned more than once (in the
bgonline.org forum for sure, maybe here as well), but didn't really
explain as far as I can remember, is passing clear takes against weaker
players in simple endgame positions, like races or advanced anchor
holding games.

Consider this position:

GNU Backgammon Position ID: 23ZHAADb7g4AAA
Match ID : cAlgAQAAAAAE
+13-14-15-16-17-18------19-20-21-22-23-24-+ O: GNUbg
| O | | O O O O O O | 0 points
| | | O O O O O O |
| | | O O |
| | | |
| | | |
v| |BAR| | 11 point match (Cube: 1)
| | | |
| | | |
| | | X X X |
| | | X X X X X X | On roll
| | | X X X X X X | 0 points
+12-11-10--9--8--7-------6--5--4--3--2--1-+ X: You
Pip counts : O 62, X 57

Between equal players, this is a straightforward D/T, any different
action is en error of about 0.1.

If X is weaker than O by 3 PR points, it is a pass!

This is not a contrived situation. Simple endgames are common, someone
weaker than the top players by 3 PR is about at the middle of the field
in your typical open tournament.

The "tactical" qualifier in your question may not even be needed. This
is only mathematics, the uneven curvature of the equity when X and O are
of different skills, something like that. There are a few real
mathematicians here that could certainly express it more rigorously.

Of course you have to realize that it may matter, then study when and
how much it does, then decide that, when it's the right thing to do, you
will do it and silently laugh at the raised eyebrows of the kibitzers.

On October 16, 2021 at 2:47:43 PM UTC-6, Philippe Michel wrote:

> On 2021-10-13, MK <mu...@compuplus.net> wrote:

>> On the "Planet of PRs", why would any ape make "PR
>> sacrificing moves for tactical reasons"?

> Because in some circumstances it's the right thing to do.
> Why else ?

What determines it to be the right thing to do?

> An example that Stick casually mentionned more than once
> (in the bgonline.org forum for sure, maybe here as well), but
> didn't really explain as far as I can remember, is passing clear
> takes against weaker players in simple endgame positions,
> like races or advanced anchor holding games.

I would like to see him try to "explain" it and make an ass out
of himself. For being a professional gambler, he probably will
not give out his wisdom for free but we can pass the hat to
pay him for what he may be worth...
> Consider this position:
> Between equal players, this is a straightforward D/T, any
> different action is en error of about 0.1.

I don't understand but I would like to understand and make an
effort to do.

> If X is weaker than O by 3 PR points, it is a pass!

> The "tactical" qualifier in your question may not even be needed.
> This is only mathematics, the uneven curvature of the equity
> when X and O are of different skills, something like that.

Yeah, it sound something like pure bullshit to me.

> There are a few real mathematicians here that could certainly
> express it more rigorously.

Let's hope that they will endow us all with their deep knowledge
of math as applicable to the issue...

> Of course you have to realize that it may matter, then study
> when and how much it does, then decide that, when it's the
> right thing to do, you will do it and silently laugh at the raised
> eyebrows of the kibitzers.

I agree but we can't apply this backwards. Whoever can claim
to be able to do this needs to demonstrate with a few examples
where he will declare what he will do before the move. And also,
hopefully enough "big apes" will contribute so that statistically
we will see if it actually pays off or not.

Since you are willing to engage, let me ask a few more questions
in trying to understand better.

1) Isn't PR is the average of checker and cube errors? If so, how
would that "uneven curvature of the equity mathematics" apply
"when X and O are of different skills" of checker and cube play
separately and disproportionately?

If my question is clear enough, feel free to answer. If not, I'll be
galad to reword it and clarify further.

2) a- Since this is obvious and common knowledge, what would
keep the underdog from manipukating it to his advantage?
b- Especially if the average PR underdog by +3, is in fact stronger
in checker or cube PR and can use this to his advantage in positions
where being better in checker or cube skill matters and coincides
with his being better in checker or cube skill?

Again, I hope you will understand my question but if not, I will try
to reword it to make it clearer for you.

3) As a minor issue, does a player's PR stay static forever? What
if the underdog improves and/or the favorite declines in PR?

4) a- As a minor issue, does PR equate to "predictability"? What if
the opponent doesn't do the expected decision? Is the "tactical"
PR sacrificing move still beneficial?
b- If a human player makes such tactical moves against a bot
rated at +3 PR and also perfectly consistent/predictable, can you
run a test to prove that they will even benefit in that case?

Anyway, I don't want to over-try complicating this unnecessarily
since even a few monkey wrenches are enough to show that you
are being very simplistic and "amateur" at debating both sides
of the issue here. You are trying to re-sell what you have already
been sold...

MK

On 2021-10-18, MK <murat@compuplus.net> wrote:

> Since you are willing to engage, let me ask a few more questions
> in trying to understand better.
>
> 1) Isn't PR is the average of checker and cube errors? If so, how
> would that "uneven curvature of the equity mathematics" apply
> "when X and O are of different skills" of checker and cube play
> separately and disproportionately?

I think it doesn't matter, but note that what I described, while not
rare, is a relatively specific situation. The general idea is "if the
opponent butchers games that are average to difficult, keep the cube low
in the ones that are easy". How exactly he misplays the difficult games
is not important.

> 2) a- Since this is obvious and common knowledge, what would
> keep the underdog from manipukating it to his advantage?

He can't do that, since it applies in simple situations where unnatural
plays will be errors and cannot distract the stronger opponent.
> b- Especially if the average PR underdog by +3, is in fact stronger
> in checker or cube PR and can use this to his advantage in positions
> where being better in checker or cube skill matters and coincides
> with his being better in checker or cube skill?

Again, this applies in positions where little skill is needed.

> 3) As a minor issue, does a player's PR stay static forever? What
> if the underdog improves and/or the favorite declines in PR?

Of course PR vary, and is never really known precisely (be it that of
the opponent or even one's own).

> 4) a- As a minor issue, does PR equate to "predictability"?

Since a low PR means playing closer to the bot, yes, a low PR implies
more predicatble play.

> b- If a human player makes such tactical moves against a bot
> rated at +3 PR and also perfectly consistent/predictable, can you
> run a test to prove that they will even benefit in that case?

I'm not sure what you mean. Is "they" the human player and the bot
playing at a weakened level ? In this case, if the bot's weakening is
cleverly done and it makes errors in "humanly" difficult positions but
not in simple ones, I think "they" will benefit as well. If the bot is
weakend by adding some random noise to evaluations of all positions it
won't work since every position will be similarly "difficult" to it.

On October 19, 2021 at 4:35:26 PM UTC-6, Philippe Michel wrote:

> On 2021-10-18, MK <mu...@compuplus.net> wrote:
>> 1) Isn't PR is the average of checker and cube errors? If so, how
>> would that "uneven curvature of the equity mathematics" apply
>> "when X and O are of different skills" of checker and cube play
>> separately and disproportionately?

> I think it doesn't matter,

How not? If one player is 4 cube PR and 6 checker PR, with an
average 5 PR. If the other player 12 cube PR and 4 checker PR,
with an average 8 PR (i.e. 3 worse than the other). How can you
claim that an average 5 PR can exploit the 8 PR but a 4 checker
PR can't exploit a 6 checker PR or that a 4 cube PR can exploit
a 12 cube PR even worse...??

> The general idea is "if the opponent butchers games that are
> average to difficult, keep the cube low in the ones that are easy".

Right here, before we go on, let's make a record of what you are
saying: "stronger player should not give the weaker player a chance
to get lucky in positions where not much checker skill is needed,
in other words "cube magnifies luck!".

Please confirm and agree.

>> 2) a- Since this is obvious and common knowledge, what would
>> keep the underdog from manipukating it to his advantage?

> He can't do that, since it applies in simple situations where unnatural
> plays will be errors and cannot distract the stronger opponent.

I don't know what "unnatural plays" really mean but this is exactly
what Paul was giving an example of in another threas with Tim's
doubling when not good enough to double because of thinking
Jim wrongly passes such takes. So, in this example Jim is the
stronger player and Tim is the weaker (i.e. +3 PR BG moron) who
is good enough to know to double only in simple end-game
positions. And Jim drops as a "tactical move sacrificing PR" by
passing a take when the other BG moron Paul argues that it is
Tim who makes a "tactical move sacrificing PR" by boubling too
early...

Which is it clowns...!?

>> b- Especially if the average PR underdog by +3, is in fact stronger
>> in checker or cube PR and can use this to his advantage in positions
>> where being better in checker or cube skill matters and coincides
>> with his being better in checker or cube skill?

> Again, this applies in positions where little skill is needed.

What skill specifically? Checker of cube? Or neither?

>> 3) As a minor issue, does a player's PR stay static forever? What
>> if the underdog improves and/or the favorite declines in PR?

> Of course PR vary, and is never really known precisely (be it that of
> the opponent or even one's own).

Okay, so, expecially since the statistically significant minimal number
of trials can't be collected in a human life span, not even mixed
results of a player againt all his oppenents, let alone his specific
results against a given opponent who's PR is not static over time,
following the advice of your daily horoscope may be as good as
any concocted bullshit BG skill...?

> > 4) a- As a minor issue, does PR equate to "predictability"?

> Since a low PR means playing closer to the bot, yes, a low PR
> implies more predicatble play.

With that, will you agree that logically the "less predictable" player
can better exploit the "more predictable" player?

>> b- If a human player makes such tactical moves against a bot
>> rated at +3 PR and also perfectly consistent/predictable, can you
>> run a test to prove that they will even benefit in that case?

> I'm not sure what you mean. Is "they" the human player and the bot
> playing at a weakened level ? In this case, if the bot's weakening is
> cleverly done and it makes errors in "humanly" difficult positions but
> not in simple ones, I think "they" will benefit as well. If the bot is
> weakend by adding some random noise to evaluations of all positions it
> won't work since every position will be similarly "difficult" to it.

This was a bad question. I retract it. I somehow think of verious bot
levels as human levels trying to do their bests. I should have known
better. Especially for being the one to argue that it makes no sense
to challenge the bots except at their highest strenghts because of the
random noise things which also allows some wiggle room for the bot
to cheat by making "PR sacrificing tactical moves" that humans can't
prove that they weren't such moves... :)))

MK

On 2021-10-20, MK <murat@compuplus.net> wrote:

> On October 19, 2021 at 4:35:26 PM UTC-6, Philippe Michel wrote:
>
>> On 2021-10-18, MK <mu...@compuplus.net> wrote:
>
>>> 1) Isn't PR is the average of checker and cube errors? If so, how
>>> would that "uneven curvature of the equity mathematics" apply
>>> "when X and O are of different skills" of checker and cube play
>>> separately and disproportionately?
>
>> I think it doesn't matter,
>
> How not? If one player is 4 cube PR and 6 checker PR, with an
> average 5 PR. If the other player 12 cube PR and 4 checker PR,
> with an average 8 PR (i.e. 3 worse than the other). How can you
> claim that an average 5 PR can exploit the 8 PR but a 4 checker
> PR can't exploit a 6 checker PR or that a 4 cube PR can exploit
> a 12 cube PR even worse...??

You can't average PRs like this. First, as far as I know, XG doesn't
have separate numbers for checker and cube play. GNUbg does but they
must be weigthed by the number of decisions (non-forced checker moves and
what it calls "actual or close cube decisions").

In general, checker play error rate matters more (3 times more ? 5 times
more ? that's in this area).

>> The general idea is "if the opponent butchers games that are
>> average to difficult, keep the cube low in the ones that are easy".
>
> Right here, before we go on, let's make a record of what you are
> saying: "stronger player should not give the weaker player a chance
> to get lucky in positions where not much checker skill is needed,
> in other words "cube magnifies luck!".
>
> Please confirm and agree.

I can't since I didn't say that... I never implied checker skill
specifically.

Anyway, cube doesn't magnify luck. When accepted (not all the time,
then), cube magnifies the stake. Lucky events become twice as lucky and
errors become twice as expensive. The luck-to-skill ratio is unchanged.

Moreover, cubeful play adds a series of pure skill decisions to the
checker play : should I double ? shoud I double ? ... he doubled, should
I take ? These dilute the cubeless luck-to-skill ratio. Cube diminishes
the influence of luck.

On 2021-10-20, MK <murat@compuplus.net> wrote:

>> > 4) a- As a minor issue, does PR equate to "predictability"?
>
>> Since a low PR means playing closer to the bot, yes, a low PR
>> implies more predicatble play.
>
> With that, will you agree that logically the "less predictable" player
> can better exploit the "more predictable" player?

Predictability here is somehow a weaker concept than in other games
(typically card games) where parts of the "position" to evaluate are
hidden and Bayesian reasoning (he did this, then he is more likely to
have that) is an important part of trying to evaluate it.

All I mentionned is that some kind of positions are easier to play and
other are harder, and it is predictable that people make more errors in
the second case. Here, the more predictable the opponent is, the less
there is to exploit.

Moreover, in so-called incomplete information games, unpredictability is
a "defensive" skill, merely making you harder to exploit. Your own
unpredictability doesn't help to see through that of the opponent. The
"can better" in your words above doesn't really make sense.

On October 24, 2021 at 6:52:12 AM UTC-6, Philippe Michel wrote:

> On 2021-10-20, MK <mu...@compuplus.net> wrote:
>> How not? If one player is 4 cube PR and 6 checker PR, with an
>> average 5 PR. If the other player 12 cube PR and 4 checker PR,
>> with an average 8 PR (i.e. 3 worse than the other). How can you
>> claim that an average 5 PR can exploit the 8 PR but a 4 checker
>> PR can't exploit a 6 checker PR or that a 4 cube PR can exploit
>> a 12 cube PR even worse...??

> You can't average PRs like this.

Why not? Is more more important than the other? If so, how is
the average calculated?

> First, as far as I know, XG doesn't have separate numbers for
> checker and cube play.

It sure does.

> GNUbg does but they must be weigthed by the number of
> decisions (non-forced checker moves and what it calls
> "actual or close cube decisions").

You are telling me how each one is calculated. I was asking
how the average of the two is calculated.

> In general, checker play error rate matters more (3 times more ?
> 5 times more ? that's in this area).

I'm not gonna harp on you on this because I also argue that
checker skill is much more than the so called cube skill. But
we can't continue discussing before you tell me how the bot
calculates the average PR.

>>> The general idea is "if the opponent butchers games that are
>>> average to difficult, keep the cube low in the ones that are easy".
>> Right here, before we go on, let's make a record of what you are
>> saying: "stronger player should not give the weaker player a chance
>> to get lucky in positions where not much checker skill is needed,
>> in other words "cube magnifies luck!".
>> Please confirm and agree.

> I can't since I didn't say that...

You mean you never agree with anything unless you are the one
who said it??

> I never implied checker skill specifically.

Of course you did. You gave an end-game example where there
is not much need for checker skill anymore. Your point was that
checker skill didn't matter after that stage.

> Anyway, cube doesn't magnify luck. When accepted (not all the
> time, then), cube magnifies the stake. Lucky events become
> twice as lucky and errors become twice as expensive.

Exactly! In the example you gave, if the stronger player takes and
the weaker player gets lucky, he gets twice as lucky! And in an
end-game position like the ones you gave, there is not much room
for error, even if the weaker player wanted to make errors on
pusrpose; therefore at that late stage errors don't become twice
as expensive.

> Moreover, cubeful play adds a series of pure skill decisions to
> the checker play : should I double ? shoud I double ?

You mean that "should I double ? shoud I double ?" are checker
decisions...? Now I'm convinced you are an idiot indeed... :(

> ... he doubled, should I take ? These dilute the cubeless
> luck-to-skill ratio. Cube diminishes the influence of luck.

You have no idea what you are talking about. You are just
trying to preach from a book that you read but couldn't even
understand.

MK

On October 24, 2021 at 8:35:09 AM UTC-6, Philippe Michel wrote:

> On 2021-10-20, MK <mu...@compuplus.net> wrote:

>>> Since a low PR means playing closer to the bot, yes, a low PR
>>> implies more predicatble play.
>> With that, will you agree that logically the "less predictable" player
>> can better exploit the "more predictable" player?

> Predictability here is somehow a weaker concept than in other
> games (typically card games) where parts of the "position" to
> evaluate are hidden and Bayesian reasoning (he did this, then
> he is more likely to have that) is an important part of trying to
> evaluate it.

Huh??

> All I mentionned is that some kind of positions are easier to play
> and other are harder, and it is predictable that people make more
> errors in the second case. Here, the more predictable the opponent
> is, the less there is to exploit.

Exactly. The bots are the most predictable of all because they always
make the same moves in given positions. So, no ape on the planet of
PR's would make a PR sacrificing move against a predictable opponent.

Yet, the whole idea of PR sacrificing tactical moves is based on the
predictability of the opponent. So, if an ape on the planet of PR's is
playing against an unpredictable human opponent, why in hell would
he make a PR sacrificing tactical move..?

This was and still is the question!
>
> Moreover, in so-called incomplete information games, unpredictability
> is a "defensive" skill, merely making you harder to exploit. Your own
> unpredictability doesn't help to see through that of the opponent. The
> "can better" in your words above doesn't really make sense.

My argument may not make sense to you in your little world but does
make sense on the planet of PR's...

MK