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Forum (blue) No Double, 5-3 to play:

jGfwADSMZ+EBUA:cImuACAAAAAA

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B/20 13/10 to enable and give us a chance to build...6/3 is nice as it gives us a chance to make the 2point, but do we want the 2?, we could play safe and tidy up, but we r 2-0 down and need to pressure; if we are hit, rkb's board is not yet fearful so i advocate leaving this extra blot, which can only be hit indirectly

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Wow, placing my vote reveals 4 players have 4 different opinions here already :laugh:
Ok - well here is why I disagree with stog's 13-10 - and of course we are only talking about where the 3 goes, I am totally happy with the bar 20 part of it  ;).  

13-10 is another blot, making 4 in total. As RKB stated in the last move that is just too many - and RKB hasnt even got anything on the bar!! Then 9-6 - nope, it just stacks and adds nothing to what we have here. So, 6-3 or 24-21 left... hmmm 6-3 is ok...but goes a bit too deep too early, ooer missus... :laugh: :laugh: Thus leaving only 24-21.

Hence my choice of 24-21, it will move us forward and doesn't add any extra blots. If we get hit on either 20 or 21, we can hope to anchor on the other one - or use the blots to cover RKB bringing down those all important men he talked about in the last move.  He needs blots in his outer board - and we need to catch them  ;)

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Bar/20 is forced.  Where to take the 3?  I don't like stacking another checker on the 6.  A spare on the three doesn't buy us much.  So I narrow the choice to 13/10 or 24/21:

Bringing down another builder with 13/10 looks ok - it puts pressure on the board and makes it likely that we'll make a valuable.point in a roll or two. But, with the split backmen a second outfield blot is perhaps not such a good idea. 

24/21 is more cautious in the sense that we don't leave another blot.  Being ahead in the race makes me want to err on the side of safe play.  OTOH, being behind in the match makes me want to play boldly.  13/10 is certainly the bolder play.

rkb doesn't have much of a board, so let's go for it.  13/10

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hmm  my choice of 24/20, 8/5 isn't even on the list.

Quote from: roadkillbooks on July 14, 2009, 05:11:21 PMhmm  my choice of 24/20, 8/5 isn't even on the list.

:lol: I'm sure it's on GnuBg's list though  - as Awful!

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Moves like 6/3 are almost always frowned on by GnuBg when the piece gets put past where it belongs, which is the 5-point or the 4-point.

9/6 is tidy and safe and it's not too bad a stack, given that it's topping up the 6-point to its original 5. I don't care for that, though.

13/10 is nice and aggressive and if killroadblocks's three men can be contained then there could be a juicy sizzle of cubed gammon in the air. I don't care for the risk though. If we get hit then it's goodbye to out generous pip lead.

24/21 is the racing move. Generally I don't like having two blots on the opponent's high home points but I think the risk is less than that of 13/10, mainly because the 8-point is stripped (although 4-4 would be a very unfunny joker, a joker which gives added value to the 9/6 safety move).

Overall I'm in favour of racing and keeping down the blot count without being completely driven by safety-mindedness.

bar/20, 24/21

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Quote from: roadkillbooks on July 14, 2009, 05:11:21 PM
hmm  my choice of 24/20, 8/5 isn't even on the list.

I just can't see that - can you write a detailed explanation of the advantages of that move for me please....

:lol: 

For me the advantages are clear...forum could take advantage of my weaker board by offering multiple shots and getting into a viable backgame.  :thumbsup2: Although this would be better at a 3-0 score, the forum could then double me and I wouldnt be able to take advantage of any gammons. :icon_pidu: :icon_pidu: :icon_pidu:

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I've been on vacation for the last 2 weeks and see that the forum team has slacked off badly in my absence, especially as far as my dice generator is concerned. I will resume rolling duties going forward. In the meantime, I would recommend not leaving more blots than necessary and wouldn't mind moving the 6-3, so as to maybe get some shots in at the 3 pieces roadie has in our home board. He will be attacking our blot on the 5 point if he has any chance at it, and I don't want to leave a lot of strays to turn this into a rout.

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Quote from: lewscannon on July 14, 2009, 10:02:51 PM
He will be attacking our blot on the 5 point if he has any chance at it

attacking? With what?  He's got a stripped eight point and no builders.  Unless he rolls 31 or 11 he's hitting loose at best.

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rkb now has backcheckers on 24 and 23, similar to an opponent that splitted with a 1. The result is that his indirect shots in our outfield are doubled. The blot on 9 gets hit with sevens and eights, which adds up to 11 shots, already the same as a direct 1-shot. Playing 13/10 adds nines as hitters, and leaves rkb quite a few hitting numbers. Also, if there's anything rkb would like to do here, it is to get his three backcheckers moving. Giving him targets to do so in realtive safety seems wrong to me.

6/3 is just bad technique here, the spare on 3 would have almost no place to go, and especially with the made threepoint, we should be focussing on the higher points. Worst alternative because of the inflexibility and wrong priorities.

So, the choice is between 24/21 and 9/6. They both have some pluses and minuses, 24/21 gives rkb more to attack, and even if it's just a loose hit, it would mean that our builder on the 9pt won't get used, and is more of an extra target actually. But with rkb's stripped eightpoint, the risk of this play is not that high. It does prepare well for a high anchor, or to run a checker, both of which are good with our race lead.

9/6 also leaves the backcheckers in a good position, the 24,20 split is valuable. It takes away 11 shot hitting numbers, which is pretty valuable considering that rkb wants to move those backmen. The downside is obvious: it takes away the builder and stacks it on our 6. Since our 5 and 4 are open, the checkers on 6 will probably find their way, so I'm not too bothered by putting 5 men there. Losing the builder hurts a bit though, but at least we still have the eightpoint.

Tough choice, I picked 9/6 under the motto of KISS (keep it simple, stupid)! We got our advantage, let's not spoil that by offering targets.

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I like 6/3 here just because of the 2 pt waiting to be hit.  It seems the only logical move to me and at least one someone agrees with me.   :)

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So there!   :laugh:

socksey



"Doubt is not a pleasant condition, but certainty is absurd." - Voltaire

Quote from: ah_clem on July 14, 2009, 11:35:25 PM

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attacking? With what?  He's got a stripped eight point and no builders.  Unless he rolls 31 or 11 he's hitting loose at best.

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With any kind of roll that makes sense, even if hitting loose (lews?) and especially if he can hit twice somehow. He has the beginnings of a good back game going here if that fails. This is what I'd be looking to do if I were him.

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Both 9/6 and 6/3 looks unnatural and supersafe. I would do these moves only if we had already escaped both checkers. I voted for most natural 13/10 but I didn't realise that it leaves so many shots like Zorba said. So that leaves only 24/21 which leaves more attack chances. Differences can't be big here. Nothing looks very good.

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13/10. we need more builders while his board is not too strong.

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Well, this is a very interesting vote. Right now it's tied with two moves at 4 votes, one 3 and one 2.

If there will be a tie, I think a decent solution might be to pick the move that got all its votes (4 right now) first, if I know which play that was (for now, I know)  :happy:

Quote from: Zorba on July 15, 2009, 10:31:22 PM
Well, this is a very interesting vote. Right now it's tied with two moves at 4 votes, one 3 and one 2.

If there will be a tie, I think a decent solution might be to pick the move that got all its votes (4 right now) first, if I know which play that was (for now, I know)  :happy:

I'd rather there be a brief pause while

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we persuade some 6/3s to go for 24/21! ;)

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Since 24-21 now has 5, 1 ahead of the nearest, I am gonna hush my mouth and cross my fingers  ;)  :laugh: :laugh:

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What would a good player do here? Not play 6-3 for sure. The spares on the 6pt are for making the 5 and 4pts. 9/6 is surely too tame; restacking an already fat point is occasionally right when you already have a good position that can come home fairly easily as it stands, but that isn't the case here. 13/10 looks too big to me, four blots is a lot of weight to carry at a time when the opponent is keen to hit. Here it gives him good 6-3 and 5-4, numbers that are not very good otherwise. This just leaves 24/21, which is quite reasonable. I vote for that.

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Quote from: Zorba on July 15, 2009, 10:31:22 PM
If there will be a tie, I think a decent solution might be to pick the move that got all its votes (4 right now) first, if I know which play that was (for now, I know)

Hmmm. Early votes count extra?  I don't think that's a good idea.

My suggestion on what to do if it's tied (and it looks like this one isn't going to be):

either
A) have a short run-off period where those who voted for the third and lower choices are encouraged to change their vote to one of the top two.
or
B) the moderator/facilitator (Zorba in this match) makes the call, based on the reasoning presented in the comments.

Flipping a coin, or giving extra weight to early votes is not a good way to settle it.

With cube decisions, I'd suggest a tie is no-double.  For take decisions, a tie is no-take.  i.e. you need a majority to make or accept a double. 

I don't like extending the vote period, 2 days is more than enough IMO and everyone can change their vote at every point, so more time won't  really change anything in this process and just slow the match down I'm afraid.

I'm not a fan of the idea that I would decide the best move on subjective criteria, it would mean I would have to value some people's comments higher than others people's. Not a good idea IMO and personally I find it unworkable, as I usually have bot results in front of me by that time. So, instead of tossing a coin when the vote is tied, I think the method I described is at least slightly more satisfying. Encouraging early voting in itself isn't too bad either  :)

I dont think that 2 days is more than enough. The tie may not become apparent until late in the time frame and some people may not get to see it and take action. An extra day for further discussion, persuasion and vote changing will slow the match down but it's an assumption that that's a bad thing. I'm certainly not in such a great hurry that I'd rather have an arbitrary decision than one that we've come to ourselves.

Perhaps we 'd benefit from a poll about what tie-breaking method people would prefer?

Quote from: Zorba on July 16, 2009, 08:55:54 PM
So, instead of tossing a coin when the vote is tied, I think the method I described is at least slightly more satisfying. Encouraging early voting in itself isn't too bad either  :)

One way to think about your method is to make the result "sticky".  i.e. When the first vote is cast, that choice becomes the presumptive outcome.  As more votes come in, the result doesn't change until another choice gets more votes than it and takes an actual lead - ties do not change the leader.   

I don't know how difficult it would be to implement this, but if you can see timestamps of various votes you can just look at the last timestamp of the tied choices to figure it out.

I'm ok with this method.  Since people can change their vote any time, if it's obvious that your first choice is not garnering much support you can change to your second choice.  No need to wait until voting closes and a runoff period to switch.

 
Rollout 1296 trials, 2-ply throughout

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The voting was well split and GnuBg's rollout reflects that. The top three moves are not well separated by the rollout. The standard deviation of error (Std Err) is large at 0.012 and so Jsds and %Confidence have been given to add perspective to the interpretation.

# .. Move ........... Equity ..(Diff) ... Win ..... WinG .. WinBg -- Lose ... LoseG . LoseBg .. Jsds .. %Confidence
1 .. bar/20 24/21 ... +0.256 ............ 53.1% .. 16.3% ... 1.3% -- 46.9% .. 15.0% ... 2.0%
2 .. bar/20 9/6 ..... +0.247 (-0.009) ... 52.9% .. 16.4% ... 1.1% -- 47.1% .. 15.0% ... 1.6% .. 0.575 .. 72%
3 .. bar/20 13/10 ... +0.235 (-0.020) ... 52.2% .. 17.3% ... 1.2% -- 47.8% .. 15.8% ... 2.6% .. 1.206 .. 88%
4 .. bar/20 6/3 ..... +0.150 (-0.106) ... 50.4% .. 16.0% ... 1.1% -- 49.6% .. 16.6% ... 2.3% .. 6.450 . 100%
Std Err (ave) ........ 0.011 ............. 0.2% ... 0.2% ... 0.1% --- 0.2% ... 0.3% ... 0.2%

For those who are keen, this article, Understanding Uncertainty (http://gammonline.com/members/Jan01/articles/uncert.htm), will go some way towards explaining what Jsds and % Confdence is about. For those who aren't, the 72% in the above table means that move #1 is probably (72% chance) better than #2 but may not be (28%) and the 88% says that move #1 is more probabably better than move #3 yet still may not (12% chance).

Essentially, the equities that a rollout gives are guesses and the true value is somewhere around. Due to the size of the standard deviation of error, there's an overlap of the ranges covering where the true equities of the three moves may be. This is why the order of the moves is not to be taken as gospel but viewed in terms of that % chance that they are correct.

Further rollout trials would reduce the Std Err and thereby increase the certainty but this was a very slow rollout (and I made a mistake that I only discovered near the end so I had to restart! :unhappy:) and so I didn't get to extend beyond the 1296.

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Quote from: playBunny on July 18, 2009, 05:13:36 PM
.. the 72% in the above table means that move #1 is probably (72% chance) better than #2 but may not be (28%) and the 88% says that move #1 is more probabably better than move #3 yet still may not (12% chance).

And the 100% means that move #1 is even more probababably better than the #4th move! :laugh:

GnuBG 0/2-ply 15552 trials rollout:

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I took a different approach, lower play settings but many more trials to get the SE down for statistical significance. A very slow rollout indeed...this took more than 24 hours to complete. Fortunately, both playBunny's and my rollouts are very much in agreement here, so it looks like this is the ordering of the plays indeed. Pretty close call here, it's interesting to take a look at the w/g/bg breakdown; you can see f.i. that the 9/6 move loses least gammons by cleaning up the blot and that 13/10 wins most gammons, being the best priming/attacking move. Leaving two blots also means it wins least games and loses most gammons, which is why it ended up third, despite the matchscore. At a score where losing gammons doesn't matter at all, and winning them is worth twice as much (like 2-away, 1-away Crawford), B/20 13/10 might just be the winner.


    1. Rollout          bar/20 24/21                 Eq.:  +0,2602
        53,02  16,41   1,20 -  46,98  14,69   1,61 CL  +0,1364 CF  +0,2602
      [  0,06   0,06   0,03 -   0,06   0,06   0,06 CL   0,0020 CF   0,0041]
    2. Rollout          bar/20 9/6                   Eq.:  +0,2490 ( -0,0112)
        52,95  16,30   1,06 -  47,05  14,34   1,47 CL  +0,1332 CF  +0,2490
      [  0,06   0,05   0,02 -   0,06   0,07   0,06 CL   0,0018 CF   0,0037]
    3. Rollout          bar/20 13/10                 Eq.:  +0,2427 ( -0,0175)
        52,44  17,25   1,20 -  47,56  15,84   2,26 CL  +0,1243 CF  +0,2427
      [  0,06   0,05   0,03 -   0,06   0,07   0,07 CL   0,0020 CF   0,0040]

Full cubeful rollout with var.redn.
15552 games, Mersenne Twister dice gen. with seed 863347199 and quasi-random dice
Play: 0-ply cubeful prune [expert]
Cube: 2-ply cubeful prune [world class]

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Thanks for your comments both, on the tied vote  :)

Quote from: ah_clem on July 17, 2009, 06:28:13 PM
One way to think about your method is to make the result "sticky".  i.e. When the first vote is cast, that choice becomes the presumptive outcome.  As more votes come in, the result doesn't change until another choice gets more votes than it and takes an actual lead - ties do not change the leader.  

I don't know how difficult it would be to implement this, but if you can see timestamps of various votes you can just look at the last timestamp of the tied choices to figure it out.

Yes, this is the idea. Unfortunately I can't see timestamps on the votes, so it depends on my own observations.

Quote from: ah_clem on July 17, 2009, 06:28:13 PM
I'm ok with this method.  Since people can change their vote any time, if it's obvious that your first choice is not garnering much support you can change to your second choice.  No need to wait until voting closes and a runoff period to switch.

Yes, this is the idea. So far, it seems that (nearly) all the votes are usually in after 36 hours or so. You can see right after voting what the outcome is, refresh the page later to do so. Then you can always change your mind to break a tie, and vote differently right away or in the remaining time.

Quote from: playBunny on July 16, 2009, 10:18:25 PM
I dont think that 2 days is more than enough. The tie may not become apparent until late in the time frame and some people may not get to see it and take action. An extra day for further discussion, persuasion and vote changing will slow the match down but it's an assumption that that's a bad thing.

Yes, it can become a tie at the very end of the voting period, but that's also the reason I don't think extending the voting period will help much; it might again lead to a tie, etc.

Consider this: Suppose you voted play A early, and it leads the poll. Near the end, the vote gets tied. Would you now switch to vote B? Seems unlikely. Now suppose you voted play A early, and play B is leading the poll. Either you switch to play B right away, if you're persuaded, or you don't. Now the vote gets tied at the end. Would you want to switch to play B now? It would win the poll anyway. So, it looks like there's not much to gain by waiting for the tie, and then extending the voting period.

Furthermore, I'm a bit skeptical based on the experience so far, about interesting discussions after the initial two day voting period, I'm afraid the vote will mostly just "sit there" and nothing much will happen. Perhaps if we get more voters and regulars here, this might work, but for now, I think it will just decrease interest.

Quote from: playBunny on July 16, 2009, 10:18:25 PM
I'm certainly not in such a great hurry that I'd rather have an arbitrary decision than one that we've come to ourselves.

Perhaps we 'd benefit from a poll about what tie-breaking method people would prefer?

What if that poll gets tied?  :laugh:

Anyhow, moving the match along is not really hurrying IMO, it's mostly about creating more and hopefully, more interesting decisions to discuss. And I don't think my method is arbitrary, obviously the choice got the most votes from the forum (along with other play(s)) so that in itself is not too bad, but also, if the play has been leading in the vote earlier on, it's a bit more likely that this play is actually the favourite if more voters would come in (not regarding vote changing).

I'm okay with a poll, but I'm not sure what the options should be. Anyone can set a poll up here, so feel free to do so!