Game 4, move 9 : Herd 2-1

[diane]

move?

[KDP]

Spoiler

of the 4 candidate plays listed the one i think i can eliminate right off is 3-1 2-1.  this play just looks the worst of the lot as it leaves a gap in our inner board and i cant believe this is correct.  my second least favorite choice is 8-7 8-6 because it stacks some checkers up and i like having that extra landing spot for our 2 outside checkers.  6-3 does cover the blot but i dont think thats a big issue at this point as i cant see any rolls for linus that would cause him to leave a shot now. it also flattens out our distribution which isnt so good, so that leaves 4-1 as my choice

[close]

[ah_clem]

Spoiler

The obvious play is to make the 3 point.  Make no transitions, make a fourth homeboard point, stay even-ended.

That said, stripping the 6 may lead to trouble later, while clearing the 8 has something to be said for it.  If we didn't still have our midpoint to clear I'd  definitely clear the 8 now.

But as it is, I like keeping the 8 as a landing place.  What's likely to happen is that we will have to clear the midpoint one checker at a time. leaving a 5/36 shot, and having another landing place ofr the second checker should help.

I'm going with the obvious play.  Make the 3 point.

[close]

[dorbel]

Spoiler

There aren't any very bad plays in the list. I would clear the 8pt, creating a spare 6 and another spare 5. I think clearing points and creating spares are more important than retaining blocking and landing points here, as we lead in the race. However, in a doubles match I wouldn't argue with a partner who wanted to make another play.

[close]

[ah_clem]

rollout

Spoiler

As Dorbel correctly spotted, there's not a big equity difference between the candidate rolls.  Presumably, gnu played 4/1 because it thought it was best, and XG rollout likes it too.  Again, XG likes slotting those open low homeboard points and keeping a spare on the 6.  Making the 3 point may seem "natural', but we probably won't get a shot very soon so having a solid homeboard is not so high on the agenda.

Clearing the 8 is what actually comes out on top in a full rollout, but it's within the margin of error - I don't concern myself with teasing out such small distinctions; it's enough for me to know that the moves are basically even.  The herd's play is an error, but a small one; too small to worry about.


XGID=--BACbCBB----B-a--acbbbb--:0:0:1:21:3:1:0:5:3

X:Herd   O:Linus
Score is X:3 O:1 5 pt.(s) match.
+13-14-15-16-17-18------19-20-21-22-23-24-+
| X     O        O |   | O  O  O  O  O    |
| X                |   | O  O  O  O  O    |
|                  |   | O                |
|                  |   |                  |
|                  |   |                  |
|                  |BAR|                  |
|                  |   |                  |
|                  |   |                  |
|                  |   | X     X          |
|             X  X |   | X  O  X     X    |
|             X  X |   | X  O  X  X  X    |
+12-11-10--9--8--7-------6--5--4--3--2--1-+
Pip count  X: 93  O: 103 X-O: 3-1/5
Cube: 1
X to play 21

   1. Rollout¹    8/7 8/6                      eq:+0.384
     Player:   64.06% (G:1.70% B:0.02%)
     Opponent: 35.94% (G:1.16% B:0.03%)
     Confidence: ±0.006 (+0.377..+0.390) - [61.9%]
     Duration: 4 minutes 44 seconds

   2. Rollout¹    4/1                          eq:+0.382 (-0.002)
     Player:   64.08% (G:2.06% B:0.09%)
     Opponent: 35.92% (G:1.62% B:0.03%)
     Confidence: ±0.007 (+0.375..+0.390) - [38.1%]
     Duration: 5 minutes 03 seconds

   3. Rollout¹    6/3                          eq:+0.365 (-0.019)
     Player:   63.25% (G:1.67% B:0.05%)
     Opponent: 36.75% (G:1.61% B:0.03%)
     Confidence: ±0.006 (+0.358..+0.371) - [0.0%]
     Duration: 4 minutes 27 seconds

   4. Rollout¹    3/1 2/1                      eq:+0.354 (-0.030)
     Player:   62.87% (G:1.60% B:0.04%)
     Opponent: 37.13% (G:1.60% B:0.05%)
     Confidence: ±0.007 (+0.347..+0.361) - [0.0%]
     Duration: 4 minutes 09 seconds

   5. 3-ply       4/3 4/2                      eq:+0.333 (-0.051)
     Player:   62.92% (G:1.48% B:0.01%)
     Opponent: 37.08% (G:1.61% B:0.02%)


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


eXtreme Gammon Version: 2.10, MET: Kazaross XG2

[close]

[Zorba]

Although differences are small, it's interesting how these "simple" moves can still cost you equity; 6/3 looks so obvious. You don't lose much with small errors like these, but since these sort of moves happen quite often it's probably worthwhile to try to understand what to look for here. It looks like it's again a matter of flexibility, and it's mostly about playing the high numbers (4,5,6).

[stog]

phew i was one of the 2 voters for that and i was beginning to have doubts! thx for posting the rollouts clem, and thx diane for facilitating, and thx Linus for playing, and thx all for your comments

and thx for that beer i was jus given and the sun and the bees and...