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slotting in the homeboard slotting in the homeboard

12-14-2014 , 12:03 PM
This thread is meant for positions in which slotting in the homeboard is first choice. Everytime I will encounter a unique one I will add it to this thread. Everyone is welcome to collaborate.

White - Pips 55

Black - Pips 108
Black to Play 4-1
Created with www.BGdiagram.com

How much equity you guess is won by slotting.
slotting in the homeboard Quote
12-14-2014 , 05:12 PM
I would guess a lot.
slotting in the homeboard Quote
12-14-2014 , 05:58 PM
Yes, it is not easy to hide QF's.

And how would you play this one?

White - Pips 55

Black - Pips 127
Black to Play 4-1
Created with www.BGdiagram.com
slotting in the homeboard Quote
12-14-2014 , 06:04 PM
I wouldn't slot without a cover. 19/15, 19/18 so we get hit by 55.
slotting in the homeboard Quote
12-14-2014 , 06:59 PM
Well, I think most of you I will surprise.

Unfortunately I can't place screenshots, in one way or the other disabled.

After 1296 untruncated worldclass rollouts slotting in

the first position cubeful results:
11/10 9/5 0.641
24/20 9/8 0.472
difference is 0.179

the second position cubeful results:
19/18 9/5 0.310
19/18 19/15 0.305
difference is 0.005

So also in the last position slotting is slightly profitable.
slotting in the homeboard Quote
12-14-2014 , 08:23 PM
Quote:
Originally Posted by yogiman
Well, I think most of you I will surprise.
In the last position slotting is slightly profitable.
That is surprising! My reasoning (and play) was the same as Networth's.

The fact that the cube has not been turned suggests that White was playing on for a gammon. Was your rollout for unlimited games?

Mike
slotting in the homeboard Quote
12-15-2014 , 06:07 AM
As you can see, -default match length- = 0, which should equate to money game, and -use of cube- is on.
slotting in the homeboard Quote
12-15-2014 , 10:21 AM
I have done a rollout on the last one for match unlimited, and it is totally even money whether you slot or not.
slotting in the homeboard Quote
12-15-2014 , 03:35 PM
Quote:
Originally Posted by yogiman
I have done a rollout on the last one for match unlimited, and it is totally even money whether you slot or not.
I am not sure what is going on here, but the slotting play ranks only fourth in the 1k GnuBg 1.04 rollouts below. I am posting the GnuBg IDs so you can check whether I have the right position.

The first rollout was made for no Jacoby, no beavers. The second rollout uses the Jacoby rule (with the same seed). It generated a similar result, with a somewhat smaller margin (slotting, in fourth place, trails the top play by only 0.009).

A more important consideration might be my choice of Supremo checker play for the rollout. Supremo uses the same 2-ply settings as World Class, except it uses a much larger move filter. On each move in a rollout, Supremo checks the top 16 plays that are within 0.32 of best using 2-ply evals. This can be very important in containment positions, because bots are notoriously weak in playing them. World class checks only the top 8 plays that are within 0.16 of best.

My 5k XG rollouts also have slotting ranked as a small error. The XG rollout using the Jacoby rule has fourth-best slotting behind by 0.016.

White - Pips 55

Black - Pips 127
Black to Play 4-1

Rollout #1 – No Jacoby, No Beavers
GnuBg ID: Ph8AALRtRgAGAw:cAkGAAAAAAAE

Code:
    1. Rollout          19/15 9/8                    Eq.:  +0.293877
       0.642928 0.000000 0.000000 - 0.357072 0.173430 0.019293 CL  +0.093133 CF  +0.293877
      [0.001384 0.000000 0.000000 - 0.001384 0.001384 0.000540 CL   0.003244 CF   0.007582]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    2. Rollout          19/18 19/15                  Eq.:  +0.293644 ( -0.000233)
       0.642356 0.000000 0.000000 - 0.357644 0.168572 0.016330 CL  +0.099809 CF  +0.293644
      [0.001366 0.000000 0.000000 - 0.001366 0.001329 0.000510 CL   0.003214 CF   0.007409]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    3. Rollout          19/14                        Eq.:  +0.287390 ( -0.006487)
       0.642083 0.000000 0.000000 - 0.357917 0.167501 0.016260 CL  +0.100405 CF  +0.287390
      [0.001408 0.000000 0.000000 - 0.001408 0.001335 0.000465 CL   0.003288 CF   0.007550]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    4. Rollout          19/18 9/5                    Eq.:  +0.274278 ( -0.019599)
       0.643044 0.000000 0.000000 - 0.356956 0.193109 0.024657 CL  +0.068322 CF  +0.274278
      [0.001349 0.000000 0.000000 - 0.001349 0.001438 0.000678 CL   0.003409 CF   0.008160]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]

Rollout #2 – Using Jacoby Rule and Beavers
GnuBg ID: Ph8AALRtRgAGAw:cAkGAAAAAAAA

Code:
    1. Rollout          19/15 9/8                    Eq.:  +0.301868
       0.642305 0.000000 0.000000 - 0.357695 0.172450 0.019663 CL  +0.092498 CF  +0.301868
      [0.001362 0.000000 0.000000 - 0.001362 0.001348 0.000466 CL   0.003180 CF   0.007496]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    2. Rollout          19/14                        Eq.:  +0.300662 ( -0.001206)
       0.642098 0.000000 0.000000 - 0.357902 0.166549 0.016428 CL  +0.101220 CF  +0.300662
      [0.001371 0.000000 0.000000 - 0.001371 0.001259 0.000405 CL   0.003190 CF   0.007500]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    3. Rollout          19/18 19/15                  Eq.:  +0.300606 ( -0.001262)
       0.641945 0.000000 0.000000 - 0.358055 0.169456 0.017018 CL  +0.097417 CF  +0.300606
      [0.001337 0.000000 0.000000 - 0.001337 0.001327 0.000414 CL   0.003214 CF   0.007409]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    4. Rollout          19/18 9/5                    Eq.:  +0.292579 ( -0.009289)
       0.643263 0.000000 0.000000 - 0.356737 0.193158 0.025161 CL  +0.068206 CF  +0.292579
      [0.001353 0.000000 0.000000 - 0.001353 0.001421 0.000653 CL   0.003401 CF   0.008689]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 766411571 and quasi-random dice
        Play: supremo 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 16 more moves within equity 0.32
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
BTW: Here is what I do to post the results of a GnuBg rollout.
  1. Select the plays you want to show in the GnuBg Move Panel. (Click the first, then hold the Shift key and click the last.)
  2. Click the copy button in the Move Panel. This opens the “Move details” window.
  3. Press Ctrl+A for “Select All,” followed by Ctrl+C for copy. This copies the move details to the Windows clipboard.
  4. Switch to the TwoPlusTwo Reply window, and click the # button to insert CODE tags in your message.
  5. Press Ctrl+V to paste in the move details you copied from GnuBg.
Mike
slotting in the homeboard Quote
12-15-2014 , 04:42 PM
You post this while I have been toiling doing research on these kind of positions. It is really frustrating, because I have been requesting for XG rollouts some messages ago.

In anyway, we are not so infallible in our play as the bot, so those results could be more practical for us vogues. From now on I refer to a full rollout when it concerns an untruncated rollout consisting of 1296 trials at worldclass level in an unlimited match.

Okay, now back to business.
Getting 2 checkers of white's stacks in the last position, so with 6 in the bearoff, gives a difference of .02, and still another 2 white checkers in the bearoff making a total of 8 gives a difference of .05. So the correlation between slotting and bornoff checkers is rather small.

With an open 4-point the results will be about the same as with the 5-point.

If instead of the 5-point the 6-point is open, the 51 dice combination will not lead to an extra blot, so the equity is somewhat less. The outcome for the following position with a full rollout:
18/13 0.286 and 17/16 10/6 0.274
White - Pips 55

Black - Pips 123
Black to Play 4-1
Created with www.BGdiagram.com

The outcome for the following position with a full rollout: 14/9 0.595 and 14/13 7/3 0.575
White - Pips 55

Black - Pips 120
Black to Play 4-1
Created with www.BGdiagram.com
This means that when there is an open 3-point you are alright to slot in case the two checkers are at the outerboard.

Things change drastically with an open 2-point. Only combinations 25 and 26 give white the opportunity to get out of jail, so the best tactic is to wait until white throws a two, and then try to hit him on his head.

Rule of thumb for these positions:
Slot always when the 4, 5 or 6-point is open, when the 3-point is open slot in case the two checkers are away from white's homeboard, and don't slot with an open 2-point.
Also for those points I assume that until 10 born-off checkers the results will not vary significantly.
slotting in the homeboard Quote
12-15-2014 , 04:54 PM
By the way, TaperMike, could you do a rollout for the first message of this thread?
slotting in the homeboard Quote
12-17-2014 , 02:39 AM
White - Pips 55

Black - Pips 108
Black to Play 4-1
XGID=aBBBB-B-AA-A---------e-eB-:0:0:1:41:0:0:0:0:10

All signs point towards slotting. Any play that slots the 5pt is miles ahead of any play that does not. We’re talking about whopper territory.
  • Black trails by a zillion. He cannot hope to sneak home while White is on the bar. He must make the 5pt in order to have any chance to win.
  • Black’s builders are in position. After slotting, he will have a double-shot to cover.
  • White has only a two-point board. In case he is hit, Black will usually have little trouble entering.
  • Black’s gap is high in his board. If White enters, it will be hard to keep him bottled up. If the gap were lower down, this might be a tougher decision.
Even with the three builders Black now has in position, waiting to make the 5pt naturally entails the repeated risk that White will enter. If that happens, it will be hard to contain him. Indeed, a significant portion of White’s entering rolls will hit one of Black’s builders.

The smaller risk is to slot. Even if hit, Black should be able to enter quickly. Usually, he will get a shot or two as White comes around the board.

As far as the downside is concerned, often it does not matter whether Black slots or not. Either way, it is going to be bad news for him if White enters. That being the case, this is probably a good time to assume White will dance. As previously noted, Black will probably survive being hit, and may be in a good position to harrass White as he heads for home.

My 20k XG rollout follows.

Mike


3-ply XG2 Rollout -- Unlimited Game, No Jacoby, No Beavers
Code:
XGID=aBBBB-B-AA-A---------e-eB-:0:0:1:41:0:0:0:0:10

X:Player 1   O:Player 2
Score is X:0 O:0. Unlimited Game
Pip count  X: 108  O: 55 X-O: 0-0
Cube: 1
X to play 41

    1. Rollout¹    11/10 9/5                    eq:+0.5747
      Player:   71.61% (G:0.00% B:0.00%)
      Opponent: 28.39% (G:11.90% B:1.32%)
      Confidence: ±0.0023 (+0.5724..+0.5770) - [97.6%]
      Duration: 5 minutes 51 seconds

    2. Rollout¹    9/5 8/7                      eq:+0.5716 (-0.0031)
      Player:   71.18% (G:0.00% B:0.00%)
      Opponent: 28.82% (G:12.52% B:1.48%)
      Confidence: ±0.0020 (+0.5696..+0.5736) - [2.4%]
      Duration: 5 minutes 01 second

    3. Rollout²    9/5 6/5                      eq:+0.5009 (-0.0738)
      Player:   68.68% (G:0.00% B:0.00%)
      Opponent: 31.32% (G:13.98% B:1.56%)
      Confidence: ±0.0050 (+0.4959..+0.5059) - [0.0%]
      Duration: 1 minute 37 seconds

    4. Rollout²    24/20 8/7                    eq:+0.4767 (-0.0980)
      Player:   69.06% (G:0.00% B:0.00%)
      Opponent: 30.94% (G:12.93% B:0.71%)
      Confidence: ±0.0071 (+0.4697..+0.4838) - [0.0%]
      Duration: 3 minutes 17 seconds

    5. Rollout²    24/19                        eq:+0.4696 (-0.1051)
      Player:   68.85% (G:0.00% B:0.00%)
      Opponent: 31.15% (G:13.13% B:0.75%)
      Confidence: ±0.0070 (+0.4627..+0.4766) - [0.0%]
      Duration: 3 minutes 02 seconds

    6. Rollout²    24/20 11/10                  eq:+0.4026 (-0.1721)
      Player:   67.53% (G:0.00% B:0.00%)
      Opponent: 32.47% (G:12.98% B:0.76%)
      Confidence: ±0.0054 (+0.3972..+0.4080) - [0.0%]
      Duration: 2 minutes 54 seconds

¹  20736 Games rolled with Variance Reduction.
   Dice Seed: 67516426
   Moves: 3-ply, cube decisions: XG Roller

²  5184 Games rolled with Variance Reduction.
   Dice Seed: 67516426
   Moves: 3-ply, cube decisions: XG Roller

Rollout by Taper_Mike
2014-Dec-16
eXtreme Gammon Version: 2.10.199.2658
Flashcard PositionID 000935.xgp

Last edited by Taper_Mike; 12-17-2014 at 02:45 AM.
slotting in the homeboard Quote
12-17-2014 , 08:01 AM
Thanks for your tip about the display of the rollout. I will bring it into practice now.

I mentioned that in these positions that the number of checkers born off has little effect on the slotting strategy. The following position shows that the previous results roughly hold just when white has got the 2 and 4 points.

White - Pips 37. Match Score 0/64

Black - Pips 127. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com

Code:
    1. Rollout          19/14                        Eq.:  -0,712
       0,381 0,000 0,000 - 0,619 0,205 0,060 CL  -0,504 CF  -0,712
      [0,001 0,000 0,000 - 0,001 0,001 0,001 CL   0,003 CF   0,010]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767116748 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    2. Rollout          19/18 9/5                    Eq.:  -0,725 ( -0,013)
       0,382 0,000 0,000 - 0,618 0,213 0,069 CL  -0,520 CF  -0,725
      [0,002 0,000 0,000 - 0,002 0,001 0,001 CL   0,003 CF   0,011]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767116748 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
    3. Rollout          19/15 9/8                    Eq.:  -0,730 ( -0,017)
       0,380 0,000 0,000 - 0,620 0,211 0,059 CL  -0,512 CF  -0,730
      [0,001 0,000 0,000 - 0,001 0,001 0,001 CL   0,003 CF   0,010]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767116748 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
The equity difference of the slotting move is in red, and is negligible. (For the few who don't know, there is a horizontal bar downunder).
slotting in the homeboard Quote
12-17-2014 , 09:06 AM
Slotting gets it's value mainly by the fact that there is a gap between white's homeboard points. But what if white occupies points 2 and 3? All rollouts fulfill the following criteria:
Code:
 Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767026616 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
open 6 point:
White - Pips 50. Match Score 0/64

Black - Pips 115. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
  1. Rollout          13/12 10/6                   Eq.:  +0,337
       0,656 0,000 0,000 - 0,344 0,169 0,019 CL  +0,123 CF  +0,337      
   2. Rollout          24/20 13/12                  Eq.:  +0,330 ( -0,007)
       0,641 0,000 0,000 - 0,359 0,173 0,011 CL  +0,098 CF  +0,330
   3. Rollout          14/10 13/12                  Eq.:  +0,289 ( -0,048)
       0,629 0,000 0,000 - 0,371 0,155 0,011 CL  +0,091 CF  +0,289
Slotting is okay when both checkers are out of white's homeboard.

open 5-point
White - Pips 50. Match Score 0/64

Black - Pips 116. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
         1. Rollout          14/10 13/12                  Eq.:  +0,282
       0,625 0,000 0,000 - 0,375 0,166 0,014 CL  +0,069 CF  +0,282
         2. Rollout          13/12 9/5                    Eq.:  +0,272 ( -0,009)
       0,632 0,000 0,000 - 0,368 0,185 0,018 CL  +0,060 CF  +0,272
         3. Rollout          24/20 13/12                  Eq.:  +0,267 ( -0,014)
       0,619 0,000 0,000 - 0,381 0,177 0,011 CL  +0,049 CF  +0,267
As with open 6 point.

open 4-point
White - Pips 50. Match Score 0/64

Black - Pips 108. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com


Code:
    1. Rollout          24/20 12/11                  Eq.:  +0,421
       0,650 0,000 0,000 - 0,350 0,114 0,005 CL  +0,181 CF  +0,421
    2. Rollout          12/11 8/4                    Eq.:  +0,376 ( -0,044)
       0,661 0,000 0,000 - 0,339 0,141 0,011 CL  +0,169 CF  +0,376
It is not worth slotting anymore.
slotting in the homeboard Quote
12-17-2014 , 09:58 AM
I still like to simplify the conclusions of the above post. The next position shows that in the above case it is okay to slot with an open 6-point (and 5-point) when one checker gives coverage:


White - Pips 50. Match Score 0/64

Black - Pips 119. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
    1. Rollout          24/20 19/18                  Eq.:  +0,224
    2. Rollout          12/11 10/6                   Eq.:  +0,213 ( -0,011)
       0,626 0,000 0,000 - 0,374 0,192 0,023 CL  +0,036 CF  +0,21
    3. Rollout          19/15 12/11                  Eq.:  +0,185 ( -0,038)
       0,604 0,000 0,000 - 0,396 0,200 0,019 CL  -0,013 CF  +0,185
      [0,001 0,000 0,000 - 0,001 0,001 0,000 CL   0,003 CF   0,007]
       

 Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767026616 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
slotting in the homeboard Quote
12-17-2014 , 10:06 AM
The next position shows the value of slotting with white's 2 and 3-point when there is good coverage. In this case it is exactly 0.1 equity gain.

White - Pips 40. Match Score 0/64

Black - Pips 109. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
    1. Rollout          11/10 9/5                    Eq.:  -0,295
       0,446 0,000 0,000 - 0,554 0,169 0,041 CL  -0,320 CF  -0,295
    2. Rollout          24/20 11/10                  Eq.:  -0,395 ( -0,100)
       0,422 0,000 0,000 - 0,578 0,175 0,025 CL  -0,356 CF  -0,395
slotting in the homeboard Quote
12-17-2014 , 04:38 PM
Now I am going to look what happens if white occupies the 3 and 4-point.

Code:
 Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 767259618 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
Open 6-point

White - Pips 46. Match Score 0/64

Black - Pips 126. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/14 10/6                   Eq.:  -0,356
       0,457 0,000 0,000 - 0,543 0,217 0,061 CL  -0,365 CF  -0,356
      
    2. Rollout          19/10                        Eq.:  -0,383 ( -0,027)
       0,438 0,000 0,000 - 0,562 0,215 0,039 CL  -0,380 CF  -0,383
Slotting seems to be right, but it is only apparent.

open 5-point

White - Pips 46. Match Score 0/64

Black - Pips 119. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
    1. Rollout          24/23 9/5                    Eq.:  -0,178
       0,503 0,000 0,000 - 0,497 0,166 0,044 CL  -0,206 CF  -0,178
      
    2. Rollout          11/10 9/5                    Eq.:  -0,229 ( -0,050)
       0,488 0,000 0,000 - 0,512 0,175 0,045 CL  -0,245 CF  -0,229
      
    3. Rollout          24/19                        Eq.:  -0,298 ( -0,119)
       0,463 0,000 0,000 - 0,537 0,204 0,037 CL  -0,316 CF  -0,298
This shows that the 1 should be played 24/23, but in most cases we don't throw a 1, so that's why I take 54 again:

White - Pips 46. Match Score 0/64

Black - Pips 127. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/10                        Eq.:  -0,315
       0,463 0,000 0,000 - 0,537 0,197 0,047 CL  -0,319 CF  -0,315
     
    2. Rollout          19/14 9/5                    Eq.:  -0,335 ( -0,020)
       0,466 0,000 0,000 - 0,534 0,207 0,055 CL  -0,332 CF  -0,335
Not slotting is slightly superior, because it brings a second checker pointing on the open gap. Compare with 19/10 in the first example, where the two checkers are on one point, so not diversified.

open 4-point

White - Pips 46. Match Score 0/64

Black - Pips 128. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/10                        Eq.:  -0,079
       0,525 0,000 0,000 - 0,475 0,171 0,044 CL  -0,166 CF  -0,079
      
    2. Rollout          24/19 8/4                    Eq.:  -0,351 ( -0,272)
       0,471 0,000 0,000 - 0,529 0,238 0,040 CL  -0,337 CF  -0,351
     
    3. Rollout          24/20 24/19                  Eq.:  -0,479 ( -0,400)
       0,450 0,000 0,000 - 0,550 0,283 0,017 CL  -0,403 CF  -0,479
In this case bringing a second pointer is so much superior (I stopped the rollout prematurely), that I am going to find out in one of my next posts, whether this always is a better strategy. There also could be a bug.

White - Pips 46. Match Score 0/64

Black - Pips 128. Match Score 0/64
Black to Play 4-3
Created with www.BGdiagram.com
Code:
    1. Rollout          19/12                        Eq.:  -0,187
       0,500 0,000 0,000 - 0,500 0,184 0,044 CL  -0,228 CF  -0,187
      
    2. Rollout          19/16 8/4                    Eq.:  -0,226 ( -0,038)
       0,496 0,000 0,000 - 0,504 0,194 0,053 CL  -0,255 CF  -0,226
     
    3. Rollout          24/17                        Eq.:  -0,388 ( -0,201)
       0,447 0,000 0,000 - 0,553 0,256 0,041 CL  -0,405 CF  -0,388
My conclusion for now is that in these cases it is better to wait with slotting until another pointer has arrived.
slotting in the homeboard Quote
12-18-2014 , 10:42 AM
Code:
 Full cubeful rollout with var.redn.
        42 games, Mersenne Twister dice gen. with seed 767159485 and quasi-random dice
        Play: world class 2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 8 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]
Clearly, there was a bug when I ran the position below with 54. And doing it a second time didn't help, weird. But it did work with 64.

White - Pips 46. Match Score 0/64

Black - Pips 128. Match Score 0/64
Black to Play 6-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/9                         Eq.:  -0,167
       0,503 0,000 0,000 - 0,497 0,176 0,043 CL  -0,215 CF  -0,167
     
    2. Rollout          19/13 8/4                    Eq.:  -0,179 ( -0,012)
       0,505 0,000 0,000 - 0,495 0,184 0,050 CL  -0,225 CF  -0,179
      
    3. Rollout          24/14                        Eq.:  -0,181 ( -0,015)
       0,481 0,000 0,000 - 0,519 0,190 0,029 CL  -0,259 CF  -0,181
      
    4. Rollout          24/18 8/4                    Eq.:  -0,248 ( -0,081)
       0,490 0,000 0,000 - 0,510 0,222 0,033 CL  -0,276 CF  -0,248
It shows indeed that getting a second pointer is better. It also shows that keeping the 24-point is better, unless you throw a 1.

open 3-point

White - Pips 46. Match Score 0/64

Black - Pips 129. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/14 7/3                    Eq.:  -0,157
       0,519 0,000 0,000 - 0,481 0,170 0,044 CL  -0,177 CF  -0,157
      
    2. Rollout          19/10                        Eq.:  -0,166 ( -0,009)
       0,507 0,000 0,000 - 0,493 0,166 0,032 CL  -0,186 CF  -0,166
Slotting doesn't win or lose. This changes when a second checker points on the gap.

White - Pips 46. Match Score 0/64

Black - Pips 127. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          18/9                         Eq.:  -0,099
       0,529 0,000 0,000 - 0,471 0,156 0,035 CL  -0,135 CF  -0,099
     
    2. Rollout          18/13 7/3                    Eq.:  -0,146 ( -0,047)
       0,519 0,000 0,000 - 0,481 0,168 0,043 CL  -0,174 CF  -0,146
open 2-point

again 65 is thrown, in order to get a third checker in direct range.

White - Pips 46. Match Score 0/64

Black - Pips 118. Match Score 0/64
Black to Play 6-5
Created with www.BGdiagram.com
Code:
    1. Rollout          24/18 7/2                    Eq.:  +0,051
       0,553 0,000 0,000 - 0,447 0,114 0,014 CL  -0,023 CF  +0,051
     
    2. Rollout          19/13 7/2                    Eq.:  +0,004 ( -0,046)
       0,542 0,000 0,000 - 0,458 0,113 0,023 CL  -0,053 CF  +0,004
     
    3. Rollout          19/8                         Eq.:  -0,008 ( -0,059)
       0,532 0,000 0,000 - 0,468 0,101 0,017 CL  -0,054 CF  -0,008
One move stands out, and that is slotting and moving a checker from the 24-point in order to diversify the checkers over the board. A good reason to keep the 24-point is to wait for a 1 and then to play 24/23 for a better ambush on the stacks.However, with black's homeboard blockade this is not relevant anymore, as he is able to recycle checkers now.

open 1-point : black should try to prime

Last edited by yogiman; 12-18-2014 at 10:48 AM.
slotting in the homeboard Quote
12-18-2014 , 11:55 AM
Coming back to the position at the bottom of post #14. I remarked that slotting is not productive anymore. There is only a place for a second white blot if black moves from the 24-point. Even the two outer points (5&6) in black's homeboard decrease the necessity of recycling a black checker. Probably better to get a builder on those points.
However, there should be a little correction, because 3 pointing checkers do make it profitable, though slightly:

White - Pips 50. Match Score 0/64

Black - Pips 87. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          12/7 8/4                     Eq.:  +0,589
       0,712 0,000 0,000 - 0,288 0,078 0,003 CL  +0,343 CF  +0,589
     
    2. Rollout          17/8                         Eq.:  +0,566 ( -0,023)
       0,681 0,000 0,000 - 0,319 0,020 0,001 CL  +0,341 CF  +0,566
But in case of the open 6 or 5-point there is enough gain in slotting when there is a second checker in direct range:
White - Pips 50. Match Score 0/64

Black - Pips 97. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          14/9 10/6                    Eq.:  +0,438
       0,655 0,000 0,000 - 0,345 0,145 0,006 CL  +0,159 CF  +0,438
      
    2. Rollout          17/12 14/10                  Eq.:  +0,408 ( -0,030)
       0,651 0,000 0,000 - 0,349 0,083 0,002 CL  +0,215 CF  +0,408
So to keep matters simple in the case of white's 2,3 homeboard, slot only with an open 5 or 6-point, and only when there is at least one checker backing it.
slotting in the homeboard Quote
12-19-2014 , 06:46 AM
Returning to the first position of this thread, I have been very incomplete.

Open 6-point

White - Pips 43. Match Score 0/64

Black - Pips 114. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          19/15 17/12   Eq.:  -0,222 
       0,458 0,000 0,000 - 0,542 0,184 0,016 CL  -0,285 CF  -0,222 
    
    2. Rollout          19/15 11/6     Eq.:  -0,329 ( -0,107) 
       0,444 0,000 0,000 - 0,556 0,223 0,019 CL  -0,356 CF  -0,329
Getting a second pointer is far superior. That's due to those checkers in white's outfield. On the one hand black will have a lot of opportunity of making a point in direct range next turn, on the other hand if white enters next turn there is a lot of chance he will be hit.

open 5-point

White - Pips 43. Match Score 0/64

Black - Pips 110. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          17/13 16/11   Eq.:  -0,054 
       0,507 0,000 0,000 - 0,493 0,129 0,016 CL  -0,132 CF  -0,054 
     
    2. Rollout          16/12 10/5     Eq.:  -0,093 ( -0,038) 
       0,502 0,000 0,000 - 0,498 0,154 0,030 CL  -0,182 CF  -0,093 
      
    3. Rollout          16/7                         Eq.:  -0,135 ( -0,081) 
       0,485 0,000 0,000 - 0,515 0,159 0,023 CL  -0,214 CF  -0,135
The possibility of white throwing 51 makes a lot of difference. Slotting is not very much worse than making a direct point. 16/7, three checkers in a row gives white a good chance to hit upon entering.

The following position shows that slotting is almost as good as bringing pointers. And actually we are not entirely sure, for the weakness of rollouts is that after our alternative play the bot will go on according to it's own conditioning.

White - Pips 43. Match Score 0/64

Black - Pips 112. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. Rollout          16/11 13/9     Eq.:  -0,115 
       0,495 0,000 0,000 - 0,505 0,158 0,026 CL  -0,195 CF  -0,115 
     
    2. Rollout          16/12 10/5     Eq.:  -0,129 ( -0,013) 
       0,493 0,000 0,000 - 0,507 0,167 0,027 CL  -0,208 CF  -0,129
slotting in the homeboard Quote
12-19-2014 , 03:45 PM
I skip the open 3 and 4-point, because their results are not very different from the position with an open 2-point.
White - Pips 43. Match Score 0/64

Black - Pips 99. Match Score 0/64
Black to Play 5-4
Created with www.BGdiagram.com
Code:
    1. 13/8 12/8                    Eq.:  +0,122
       0,543 0,000 0,000 - 0,457 0,056 0,004 CL  +0,027 CF  +0,122
      
    2. 15/11 7/2                    Eq.:  +0,115 ( -0,006)
       0,550 0,000 0,000 - 0,450 0,087 0,007 CL  +0,005 CF  +0,115
     
    3. 15/11 12/7                   Eq.:  +0,108 ( -0,014)
       0,534 0,000 0,000 - 0,466 0,050 0,004 CL  +0,015 CF  +0,108
Slotting is just as good as lenghtening the prime.

The position in post #16 is unrealistic with those 2 checkers on the 24 point. So let's look what is the difference in the real world

White - Pips 40. Match Score 0/64

Black - Pips 88. Match Score 0/64
Black to Play 4-1
Created with www.BGdiagram.com
Code:
    1. 14/10 13/12                  Eq.:  -0,186
       0,440 0,000 0,000 - 0,560 0,105 0,006 CL  -0,232 CF  -0,186
    
    2. 13/12 9/5                    Eq.:  -0,234 ( -0,048)
       0,447 0,000 0,000 - 0,553 0,156 0,017 CL  -0,279 CF  -0,234
Slotting has plunged 1.5 in value compared to post #16. That's because only double 5 will give white a reasonable way out, and then still can be hit in his own homeboard. At the same time black is increasing his chances considerably to fill up the gap.
slotting in the homeboard Quote
12-19-2014 , 06:11 PM
I am no professional player and am not interested in bot performance rating. My own rule of thumb for 2-point homeboard/one gap is as follows.

When not to slot:
- in case of an open 6-point
- when white has a 2-3 homeboard
- there are more than 2 of your checkers in the opponent's homeboard

In any other case I might slot. Sometimes it means a small loss of equity, and in other cases it gives a big win. What I didn't mention by the way is that it hardly loses any more gammons.

Other recommendations besides slotting:
- bring in first a second pointer
- make a point 5 or 6 away from the gap

Why should I slot when alternatives are not worse?
- you always like to put your mouth where the money is (lol)
- in order to tease your opponent (lol)
- you like to change your playing style, in the hope to influence your opponent's view about you
- he might drop a cube mistakenly, because he didn't hit
slotting in the homeboard Quote

      
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