I invite Stick to guess the correct answer based purely on the
subject line. Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

---
Tim Chow

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

On Wednesday, June 1, 2022 at 2:33:01 PM UTC+1, Tim Chow wrote:

I invite Stick to guess the correct answer based purely on the
subject line. Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

---
Tim Chow

I know this is googlable but, since you raised the topic, I'd like to inform you that
a (positive) number of people want to know what an SHA-2 hash is.

Paul

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

On 6/1/2022 5:07 PM, [email protected] wrote:

On Wednesday, June 1, 2022 at 2:33:01 PM UTC+1, Tim Chow wrote:

I invite Stick to guess the correct answer based purely on the
subject line. Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

---
Tim Chow

I know this is googlable but, since you raised the topic, I'd like to inform you that
a (positive) number of people want to know what an SHA-2 hash is.

A cryptographic hash function takes an arbitrary input and produces
an output of a fixed length (in this case, 256 bits), in such a way
that it is computationally intractable to invert it, or to find two
different inputs that produce the same output. The output is called
a hash. SHA-2 is a specific widely used cryptographic hash function.

I produced the above hexadecimal string by taking the XGID of my
position and running it through SHA-2 using the following website
(with the output size set to 256):

https://www.browserling.com/tools/sha2-hash

After Stick makes his guess, I will reveal the XGID, and anyone can
then use the website to confirm that the given XGID does indeed produce
the 256-bit hash that I have already announced. If I were to try to
bait and switch by choosing a different position after seeing what Stick guessed, I would be caught in a lie because the XGID of my altered
position would fail to produce the advertised hash.

Since SHA-2 is a deterministic function whose definition is public, one
could try to reverse-engineer the XGID from the hash. In principle this
is possible, but if you can "break" SHA-2 in this way, fame and fortune
await you. You are unlikely to be able to figure out the XGID of my
position more efficiently than by guessing position after position and
running them through the hash function to see if you happened to guess correctly.

---
Tim Chow

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

On Thursday, June 2, 2022 at 1:39:18 PM UTC+1, Tim Chow wrote:

On 6/1/2022 5:07 PM, [email protected] wrote:

On Wednesday, June 1, 2022 at 2:33:01 PM UTC+1, Tim Chow wrote:

I invite Stick to guess the correct answer based purely on the
subject line. Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

---
Tim Chow

I know this is googlable but, since you raised the topic, I'd like to inform you that
a (positive) number of people want to know what an SHA-2 hash is.

A cryptographic hash function takes an arbitrary input and produces
an output of a fixed length (in this case, 256 bits), in such a way
that it is computationally intractable to invert it, or to find two
different inputs that produce the same output. The output is called
a hash. SHA-2 is a specific widely used cryptographic hash function.

I produced the above hexadecimal string by taking the XGID of my
position and running it through SHA-2 using the following website
(with the output size set to 256):

https://www.browserling.com/tools/sha2-hash

After Stick makes his guess, I will reveal the XGID, and anyone can
then use the website to confirm that the given XGID does indeed produce
the 256-bit hash that I have already announced. If I were to try to
bait and switch by choosing a different position after seeing what Stick guessed, I would be caught in a lie because the XGID of my altered
position would fail to produce the advertised hash.

Since SHA-2 is a deterministic function whose definition is public, one
could try to reverse-engineer the XGID from the hash. In principle this
is possible, but if you can "break" SHA-2 in this way, fame and fortune
await you. You are unlikely to be able to figure out the XGID of my
position more efficiently than by guessing position after position and running them through the hash function to see if you happened to guess correctly.

Assuming the contest is not Stick-limited, I'd like to render my own guess.
I guess that the two options are extremely closely matched in terms of MWC. It's much too close to call which of these two candidate plays is correct.

Paul

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

On 6/2/2022 9:37 AM, [email protected] wrote:

Assuming the contest is not Stick-limited, I'd like to render my own guess.
I guess that the two options are extremely closely matched in terms of MWC. It's much too close to call which of these two candidate plays is correct.

I'll reveal a bit more information, which may or may not change
your guess (or Stick's guess).

I was not originally planning to pose this as a sight-unseen quiz.
As usual, I plucked the top position off my stack of puzzle positions
and came up with an impromptu subject line. Just as I was about to
post, it occurred to me that this subject line was not one of my
standard ones ("Hit?" "Break anchor?" etc.) and that Stick would
probably attempt to guess the answer from the subject line alone.
So at the last minute, I decided to give him a chance to display his
prowess at this type of puzzle.

In other words, the subject line was not premeditated specifically
to try to trip up Stick. Don't know if that helps anyone.

---
Tim Chow

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

On 6/1/2022 9:32 AM, I wrote:

I invite Stick to guess the correct answer based purely on the
subject line.  Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

Stick seems to have passed up the chance to guess the correct answer
here. I'll give it a few more days before revealing the position.

---
Tim Chow

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

On 6/1/2022 9:32 AM, I wrote:

I invite Stick to guess the correct answer based purely on the
subject line.  Here's the SHA-2 hash of the XGID so that I can't
bait and switch.

83d40149c40038da077c1ba26ae5407dce6167a299d0e6b72683eefdfa4d180a

You can cut and paste the XGID below into the following website
(with output hash size 256) to confirm the above hash value.

https://www.browserling.com/tools/sha2-hash

XGID=-CCCBBa--------B----cbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O | +---+
| X | | O O O O | | 2 |
| | | O O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 66 O: 59 X-O: 0-0
Cube: 2, O own cube
X to play 43

1. Rollout¹ 5/2 5/1 eq:-0.355
Player: 41.75% (G:0.16% B:0.00%)
Opponent: 58.25% (G:0.64% B:0.01%)
Confidence: ±0.006 (-0.360..-0.349) - [100.0%]

2. Rollout¹ 15/8 eq:-0.435 (-0.081)
Player: 37.92% (G:0.25% B:0.00%)
Opponent: 62.08% (G:1.51% B:0.02%)
Confidence: ±0.004 (-0.440..-0.431) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---------
Variant 1
---------

XGID=-CCCBBa---------B---cbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O | +---+
| X | | O O O O | | 2 |
| | | O O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 68 O: 59 X-O: 0-0
Cube: 2, O own cube
X to play 43

1. Rollout¹ 5/2 5/1 eq:-0.432
Player: 39.17% (G:0.11% B:0.00%)
Opponent: 60.83% (G:0.60% B:0.01%)
Confidence: ±0.006 (-0.438..-0.425) - [100.0%]

2. Rollout¹ 16/9 eq:-0.448 (-0.016)
Player: 37.40% (G:0.29% B:0.00%)
Opponent: 62.60% (G:1.66% B:0.02%)
Confidence: ±0.005 (-0.452..-0.443) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---------
Variant 2
---------

XGID=-CCCBBa--------B---abbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O O | +---+
| X | | O O O O | | 2 |
| | | O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 66 O: 60 X-O: 0-0
Cube: 2, O own cube
X to play 43

1. Rollout¹ 15/8 eq:-0.303
Player: 43.74% (G:1.50% B:0.03%)
Opponent: 56.26% (G:1.18% B:0.01%)
Confidence: ±0.005 (-0.308..-0.298) - [100.0%]

2. Rollout¹ 5/2 5/1 eq:-0.351 (-0.048)
Player: 41.96% (G:0.25% B:0.00%)
Opponent: 58.04% (G:0.93% B:0.01%)
Confidence: ±0.005 (-0.357..-0.346) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

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

XGID=-CCCBBa--------B----cbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O | +---+
| X | | O O O O | | 2 |
| | | O O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 66 O: 59 X-O: 0-0
Cube: 2, O own cube
X to play 43

Breaking the board wastes pips and it means that subsequent hits are
less effective since the board will be weaker. But 15/8 leaves a
direct shot and O still has a four-point board in a fairly close
race. XG favors breaking the board, but the variants below show
that there are subtleties.

1. Rollout¹ 5/2 5/1 eq:-0.355
Player: 41.75% (G:0.16% B:0.00%)
Opponent: 58.25% (G:0.64% B:0.01%)
Confidence: ±0.006 (-0.360..-0.349) - [100.0%]

2. Rollout¹ 15/8 eq:-0.435 (-0.081)
Player: 37.92% (G:0.25% B:0.00%)
Opponent: 62.08% (G:1.51% B:0.02%)
Confidence: ±0.004 (-0.440..-0.431) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---------
Variant 1
---------

XGID=-CCCBBa---------B---cbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O | +---+
| X | | O O O O | | 2 |
| | | O O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 68 O: 59 X-O: 0-0
Cube: 2, O own cube
X to play 43

1. Rollout¹ 5/2 5/1 eq:-0.432
Player: 39.17% (G:0.11% B:0.00%)
Opponent: 60.83% (G:0.60% B:0.01%)
Confidence: ±0.006 (-0.438..-0.425) - [100.0%]

2. Rollout¹ 16/9 eq:-0.448 (-0.016)
Player: 37.40% (G:0.29% B:0.00%)
Opponent: 62.60% (G:1.66% B:0.02%)
Confidence: ±0.005 (-0.452..-0.443) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---------
Variant 2
---------

XGID=-CCCBBa--------B---abbd-e-:1:-1:1:43:0:0:0:0:10

X:Player 1 O:Player 2
Score is X:0 O:0. Unlimited Game
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X | | O O O O O | +---+
| X | | O O O O | | 2 |
| | | O O | +---+
| | | O O |
| | | O |
| |BAR| |
| | | |
| | | |
| | | X X X |
| | | X X X X X |
| | | O X X X X X |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count X: 66 O: 60 X-O: 0-0
Cube: 2, O own cube
X to play 43

1. Rollout¹ 15/8 eq:-0.303
Player: 43.74% (G:1.50% B:0.03%)
Opponent: 56.26% (G:1.18% B:0.01%)
Confidence: ±0.005 (-0.308..-0.298) - [100.0%]

2. Rollout¹ 5/2 5/1 eq:-0.351 (-0.048)
Player: 41.96% (G:0.25% B:0.00%)
Opponent: 58.04% (G:0.93% B:0.01%)
Confidence: ±0.005 (-0.357..-0.346) - [0.0%]

¹ 1296 Games rolled with Variance Reduction.
Dice Seed: 271828
Moves: 3-ply, cube decisions: XG Roller

eXtreme Gammon Version: 2.19.207.pre-release

---
Tim Chow

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