5a 3a recube action from the bar

[ah...Clem]

Recube to negate gammons or hope to run this one off?

XGID=aCbBFa-a--a--------babbb--:1:-1:-1:00:2:0:0:5:10

X:X O:You
Score is X:0 O:2 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X | | X O O X O |
| | | O O X O |
| | | O O |
| | | O |
| | X | 6 |
| |BAR| |
| | | |
| | | |
| | | | +---+
| | | X X X X | | 2 |
| | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 159 O: 33 X-O: 0-2/5
Cube: 2, X own cube
X on roll, cube action

[Timothy Chow]

You don't need much of an excuse to rewhip at this score, but you do
need market losers. What loses X's market? If X dances and O rolls
62 52 42, does he lose his market? I don't think so. ND/T for me.

---
Tim Chow

[Stick Rice]

Shouldn't redouble without market losing sequence(s) and there are none. Easy hold.

Stick

[ah...Clem]

I was playing O and was surprised to see the rewhip here. But it did
make some sense - unless X turns it around he's losing a gammon most of
the time. The player stated that "I had no choice but to recube", which
isn't exactly true, but I made a note to take a look later.

As Tim and Stick observe, and the rollout confirms, no market losers
implies no cube.

In the variant, I've given X a blot to shoot at and filled in the five
point. Clear rewhip even with only a 44% GWC.

XGID=aCbBFa-a--a--------babbb--:1:-1:-1:00:2:0:0:5:10

X:Player 2 O:Player 1

Score is X:0 O:2 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X X | | X O O X O |
| | | O O X O |
| | | O O |
| | | O |
| | X | 6 |
| |BAR| |
| | | |
| | | |
| | | | +---+
| | | X X X X | | 2 |
| | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 159 O: 33 X-O: 0-2/5
Cube: 2, X own cube
X on roll, cube action

Analyzed in Rollout
No redouble
Player Winning Chances: 16.69% (G:0.00% B:0.00%)
Opponent Winning Chances: 83.31% (G:71.69% B:38.03%)
Redouble/Take
Player Winning Chances: 16.61% (G:0.00% B:0.00%)
Opponent Winning Chances: 83.39% (G:71.96% B:19.94%)

Cubeless Equities: No Double=-1.330, Double=-1.196

Cubeful Equities:
No redouble: -1.156
Redouble/Take: -1.196 (-0.040)
Redouble/Pass: +1.000 (+2.156)

Best Cube action: No redouble / Take
Percentage of wrong pass needed to make the double decision right: 1.8%

Rollout:
1296 Games rolled with Variance Reduction.
Moves: 3-ply, cube decisions: XG Roller
Confidence No Double: ± 0.008 (-1.164..-1.149)
Confidence Double: ± 0.008 (-1.204..-1.188)

Double Decision confidence: 100.0%
Take Decision confidence: 100.0%

Duration: 6 minutes 59 seconds

eXtreme Gammon Version: 2.10, MET: Kazaross XG2



Variant:

XGID=aCbAFa-a-----------bbbbb--:1:-1:-1:00:2:0:0:5:10

X:Player 2 O:Player 1

Score is X:0 O:2 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | X O O X O |
| | | O X O |
| | | O O |
| | | O |
| | X | 6 |
| |BAR| |
| | | |
| | | |
| | | | +---+

| | | X X X X X | | 2 |

| | | X X X X X | +---+
+12-11-10--9--8--7-------6--5--4--3--2--1-+

Pip count X: 149 O: 30 X-O: 0-2/5

Cube: 2, X own cube
X on roll, cube action

Analyzed in XG Roller++
Player Winning Chances: 44.57% (G:0.00% B:0.00%)
Opponent Winning Chances: 55.43% (G:39.11% B:14.09%)

Cubeless Equities: No Double=-0.471, Double=+0.026

Cubeful Equities:
No redouble: -0.101 (-0.127)
Redouble/Take: +0.026
Redouble/Pass: +1.000 (+0.974)

Best Cube action: Redouble / Take

eXtreme Gammon Version: 2.10, MET: Kazaross XG2

[Timothy Chow]

On 8/10/2022 10:59 AM, ah...Clem wrote:
> I was playing O and was surprised to see the rewhip here. But it did
> make some sense - unless X turns it around he's losing a gammon most of
> the time. The player stated that "I had no choice but to recube", which
> isn't exactly true, but I made a note to take a look later.

I've definitely heard the following kind of reasoning: "If I lose
this game, it will be a gammon loss. Therefore, I lose nothing by
redoubling." If it were literally true that 100% of your losses
were gammon losses then it would be correct that redoubling would
lose nothing. But hardly ever is it literally true that 100% of
your losses are gammon losses. Such players often forget that
sometimes they'll hit that last-ditch shot, but lose anyway after
saving the gammon. So as long as some of your losses aren't gammon
losses, you're risking *something* by redoubling, and hence you
need some reason (i.e., enough market losers) to redouble.

---
Tim Chow