Be sure to calculate the "live" cube take point first.

XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X X O | | O O O X O O |
| O | | O O O X O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| X | | X X X | | 2 |
| X X X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 150 O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

---
Tim Chow

--- SoupGate-Win32 v1.05
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On Thursday, February 9, 2023 at 9:40:18 AM UTC-5, Timothy Chow wrote:

Be sure to calculate the "live" cube take point first.

XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X X O | | O O O X O O |
| O | | O O O X O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| X | | X X X | | 2 |
| X X X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 150 O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

---
Tim Chow

Race: well behind
Advanced anchor: better than nothing
Inner board: behind
Threats: yes, about to make the 5-prime and block the blot on 2 point. 14 numbers. I give this a lot of weight.
Control of the outfield: check.

The double is not in doubt based on the upcoming prime and control of outfield.

What are the chances that white gets out and hits on the way out on this roll: it will be probably one indirect shot as O will cover if not making the prime, so, 2 immediate wins if we're generous. If white comes out and doesn't hit, there will be either
2 or 3 direct shots, say 23, so O is left with (36-23)/36 * 34 = 12 chances of scraping by, a total of 14 chances at a good shot at winning. That's 39% with comfortable room for error, and I don't think I've ever seen a take point in that territory with
a live cube. So I respectfully decline to calculate the live cube take point.

Bob

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XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X X O | | O O O X O O |
| O | | O O O X O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| X | | X X X | | 2 |
| X X X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 150 O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

Again, my comment about the live cube was sarcastic; I don't know
why people talk about a "live" cube take point in this position,
when the only relevant fact is your match winning chances trailing 5-away/2-away (about 25%).

I include a rollout below, but as in the previous problem, my main
point here is that XG 3-ply doesn't double as X. The rollout says
that this missed double is nearly a double whopper. Unlike the take
decision, the double decision is not something that can be calculated
in any straightforward manner. Leading 4-away/5-away holding a 2-cube,
one should be conscious that redoubling to 4 kills one's own gammons,
which usually means being cautious with the cube in positions with a
lot of contact. But here, X has excellent chances of making the 8pt immediately, which usually loses his market. And X's gammon chances,
while not totally negligible, aren't very high either.

Analyzed in Rollout
No redouble
Player Winning Chances: 70.57% (G:10.80% B:0.50%)
Opponent Winning Chances: 29.43% (G:11.38% B:0.33%)
Redouble/Take
Player Winning Chances: 72.54% (G:10.61% B:0.72%)
Opponent Winning Chances: 27.46% (G:15.75% B:0.87%)

Cubeful Equities:
No redouble: +0.714 (-0.170)
Redouble/Take: +0.884
Redouble/Pass: +1.000 (+0.116)

Best Cube action: Redouble / Take

Rollout:
1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.009 (+0.706..+0.723)
Confidence Double: ± 0.014 (+0.870..+0.898)

eXtreme Gammon Version: 2.19.211.pre-release, MET: Kazaross XG2

---
Tim Chow

--- SoupGate-Win32 v1.05
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On Sunday, February 12, 2023 at 10:46:33 AM UTC-5, ah...Clem wrote:

On 2/9/2023 9:40 AM, Timothy Chow wrote:

Be sure to calculate the "live" cube take point first.

XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X X O | | O O O X O O |
| O | | O O O X O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| X | | X X X | | 2 |
| X X X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 150 O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

Takepoint is about 26% if I calculated it correctly. So, a bit elevated,
but not by a lot. The gammon price is zero though if the cube is turned again.

I wouldn't ship it here. O is ahead in the race and has more homeboard points. X has a bunch of blots and is stuck on the POS three point.
Maybe O's made acepoint is enough of a liability to justify shipping it,
but I'll take a shake here and happily re-whip as O.

X wins few gammons here, but they are very valuable with the cube at 2
and worthless with the cube at 8. That's another reason to hold.

ND/T.

Rereading my first post on this position.
Must add to my list of things not to do when 2 IPA's too deep. Jeez.

--- SoupGate-Win32 v1.05
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On 2/9/2023 9:40 AM, Timothy Chow wrote:

Be sure to calculate the "live" cube take point first.

XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.  +13-14-15-16-17-18------19-20-21-22-23-24-+
 | X  X     X  O    |   | O  O  O  X  O  O |  |             O    |   | O  O  O  X     O |  |             O    |   |       O          |  |             O    |   |                  |
 |                  |   |                  |
 |                  |BAR|                  |
 |                  |   |                  |
 |                  |   |                  |
 |                  |   |                  | +---+
 |                X |   | X  X  X          | | 2 |
 |       X  X     X |   | X  X  X     O    | +---+  +12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 150  O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

Takepoint is about 26% if I calculated it correctly. So, a bit elevated,
but not by a lot. The gammon price is zero though if the cube is turned
again.

I wouldn't ship it here. O is ahead in the race and has more homeboard
points. X has a bunch of blots and is stuck on the POS three point.
Maybe O's made acepoint is enough of a liability to justify shipping it,
but I'll take a shake here and happily re-whip as O.

X wins few gammons here, but they are very valuable with the cube at 2
and worthless with the cube at 8. That's another reason to hold.

ND/T.

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

On Thursday, February 9, 2023 at 9:40:18 AM UTC-5, Timothy Chow wrote:

Be sure to calculate the "live" cube take point first.

XGID=--a-BBBB-AA--AA-Ad-bbcBab-:1:1:1:00:3:2:0:7:10

Score is X:3 O:2 7 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X X O | | O O O X O O |
| O | | O O O X O |
| O | | O |
| O | | |
| | | |
| |BAR| |
| | | |
| | | |
| | | | +---+
| X | | X X X | | 2 |
| X X X | | X X X O | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 150 O: 93 X-O: 3-2/7
Cube: 2, X own cube
X on roll, cube action

---
Tim Chow

You just really aren't understanding when/why live cube take point as a phrase is useful.

Stick

--- SoupGate-Win32 v1.05
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On 2/13/2023 4:28 PM, Stick Rice wrote:

You just really aren't understanding when/why live cube take point as a phrase is useful.

Oh, I think I understand take points and live cubes better than
you do. It's math, after all.

You complain about people using terms such as "2pt anchor". Is
that because you don't understand what people mean? Of course
not. You know what they mean. You're just claiming that this
kind of abuse of terminology interferes with deeper understanding.

I agree in general with the principle that abuse of terminology
is sometimes useful, and sometimes interferes with understanding.
Which is which has to be evaluated on a case by case basis.
The "2pt anchor" abuse of terminology is useful and harmless. To
complain about it is pedantry. On the other hand, recube vig is
a subtle topic, and even experts often misunderstand it. The term
"live cube take point" is an abuse of terminology that perpetuates
this misunderstanding. It seems to me that even you managed to
confuse yourself in the "2-away/5-away cube action" thread. You
wrote:

In this particular position if we could somehow (I'm not going to
try) tweak it so that the hits virtually won the game for the on
roll player when he hits the outfield blot and keep or better the
win % for the opponent (make the race a lot better for him?) then
half the time he'd be taking a dead cube instead of a live one
and that would be worth noting.

I can't make any sense of what you're saying, given that we're
talking about 2-away/5-away and the leader doubling. The only
change to the position that would cause us to look at what XG
calls the "dead cube" rather than the "live cube" take point is
to make it a last-roll position. (Ignoring Paul's clever
observation about the 5-away player being TG.) It looks to me
that you simply got confused because you forgot that this is a
score where there's an automatic recube. If even you get confused,
how many more other people are going to get confused? Both on
BGO and here on r.g.b., we find many people expressing confusion
(rightly so) about what the heck the "live cube take point" means.

---
Tim Chow

--- SoupGate-Win32 v1.05
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On Tuesday, February 14, 2023 at 10:12:17 AM UTC-5, Timothy Chow wrote:

On 2/13/2023 4:28 PM, Stick Rice wrote:

You just really aren't understanding when/why live cube take point as a phrase is useful.

Oh, I think I understand take points and live cubes better than
you do. It's math, after all.

You complain about people using terms such as "2pt anchor". Is
that because you don't understand what people mean? Of course
not. You know what they mean. You're just claiming that this
kind of abuse of terminology interferes with deeper understanding.

I agree in general with the principle that abuse of terminology
is sometimes useful, and sometimes interferes with understanding.
Which is which has to be evaluated on a case by case basis.
The "2pt anchor" abuse of terminology is useful and harmless. To
complain about it is pedantry. On the other hand, recube vig is
a subtle topic, and even experts often misunderstand it. The term
"live cube take point" is an abuse of terminology that perpetuates
this misunderstanding. It seems to me that even you managed to
confuse yourself in the "2-away/5-away cube action" thread. You
wrote:

In this particular position if we could somehow (I'm not going to
try) tweak it so that the hits virtually won the game for the on
roll player when he hits the outfield blot and keep or better the
win % for the opponent (make the race a lot better for him?) then
half the time he'd be taking a dead cube instead of a live one
and that would be worth noting.

I can't make any sense of what you're saying, given that we're
talking about 2-away/5-away and the leader doubling. The only
change to the position that would cause us to look at what XG
calls the "dead cube" rather than the "live cube" take point is
to make it a last-roll position. (Ignoring Paul's clever
observation about the 5-away player being TG.) It looks to me
that you simply got confused because you forgot that this is a
score where there's an automatic recube. If even you get confused,
how many more other people are going to get confused? Both on
BGO and here on r.g.b., we find many people expressing confusion
(rightly so) about what the heck the "live cube take point" means.

---
Tim Chow

I've told you several times before using the wrong terminology such as 2pt when you're actually referring to the 23pt can be confusing to new people in the game. As someone who gave a fair share of backgammon lessons and has written his fair share about
backgammon you're going to have to take my word for it. You conveniently forget this every time it comes up or you ignore it because it doesn't fit your argument, choose whichever you like.

The rest of what you wrote merely supports that you don't get it. It's fine, it won't hurt your game a lick. We had something like this around 6 months or so ago and someone else stepped in and wrote the dissertation that was needed to explain to you
what I meant and you finally got it. I'm not that guy. I don't have that energy for bg any more so maybe someone else will step up again and do my dirty work for me.

Stick

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On 2/14/2023 4:07 PM, Stick Rice wrote:

The rest of what you wrote merely supports that you don't get it. It's fine, it won't hurt your game a lick. We had something like this around 6 months or so ago and someone else stepped in and wrote the dissertation that was needed to explain to you

what I meant and you finally got it.

That was a discussion about the meaning of "whopper."
What I "got" was that the meaning of the word has drifted
away from what Magriel originally meant. But this is a
discussion about what terminology makes sense, not about
how terminology is actually used. I still think that
Magriel's originally understanding was on the right track,
but I don't care about the word "whopper" all that much,
so I'm not going to fight that battle.

As for a dissertation, the closest thing currently available
is Dirk Schiemann's "Theory of Backgammon." Schiemann does
at least recognize, as not too many people do, that the term
"live cube take point" requires careful definition. And he
offers a precise definition. If everyone were to switch over
to his definition, then most of my concerns would be addressed.
The terminology "live cube take point" would still be very
unfortunate because it's misleading and confusing, but at
least it would have a definite meaning. As thing stand now,
however, "live cube take point" is an ill-defined term. The
classical definition refers to the continuous model (this is
how Janowski uses the term, for example) but that's different
from Schiemann's definition, and probably different from what
XG uses. The XG documentation refers to "perfect redouble
efficiency" but doesn't explain what that means. It does not
seem to be the same as what GNU means by efficiency.

---
Tim Chow

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