Game 3, move 13: Forum 2-1

[Zorba]

This looks like it could be an interesting vote. Since I am away for the weekend, I set the voting period to three days this time. If anyone is in a hurry and the vote is clear, maybe diane would like to speed it up and do the next position, but perhaps it isn't necessary. At any rate, I hope there will be some good discussion on this, it's a very interesting position and dice roll! 

jDN4BgPbmGAGAw:QQmlACAAAAAA

[ah_clem]

Spoiler

Aargh.  Who let diane roll the dice?

There are no good moves here.  We either leave a bunch of blots, or bury a checker and reduce our board from four points to three.  yeech.

Mt first instinct is to play safe with a big racing lead by moving 8/6 and 3/2 or 2/1.  Then I think - we've got a four point board vs a two point board and we own the golden point - recirculating a checker  isn't so bad as any exchange of hits plays to our advantage, and we're far enough ahead in the race to take a hit in stride. Undermining our biggest strength - our board - is the last thing we want to do here. So, I'm going to dismiss all the moves in the inner board.

So, where to move elsewhere?  We can afford a single hit.  What we don't want is a double hit that leaves little counterplay . 15/13 8/7 means any double hit leaves three blots for rkb with the abandonment of the golden point.  He probably won't hit both blots even if he can.   

15/13 8/7 best of a bad lot...

[close]

[diane]

Aargh.  Who let diane roll the dice?

I get the blame for everything around here - I was in bed!!  

Spoiler

Ok, despite his wild accusations about me and the dice, I agree with the move he suggests - there is nothing much else to do with this - and I bet RKB is really glad he made that point now, it could be very useful!!

[close]

Ah_clem, the move you state you want has no other votes besides mine - did you make a button pressing error, or forget to vote?

[Zorba]

I apologize to the Forum, last night I set GnuBG's dice generator to "diane twister" by mistake.

[ah_clem]

Ah_clem, the move you state you want has no other votes besides mine - did you make a button pressing error, or forget to vote?

I must have forgotten.  I voted this am.

And now I'm off to the wilderness for a week or so; you guys will have to make do without me. While I'm away be very very careful about who you let roll the dice.

[stog]

Spoiler

8/6,3/2 leaving nothing, whereas the other moves leave multiple shots and tempo to rkb

[close]

[lewscannon]

Spoiler

This is a roll in which you try to do the least amount of damage to yourself as possible, which is why I voted the 8-6, 3-2. Hopefully we can remake the 3 point, but it seems like anything else is inviting a mess to happen. Also, in the way friends don't let drunk friends drive, please let's keep Diane away from the dice. Maybe we can give her a deck of cards to play with.

[close]

[diane]

please let's keep Diane away from the dice. Maybe we can give her a deck of cards to play with.

  I am starting to get a bit of a complex....

Spoiler

I don't know why everyone wants to be so ultra careful...we have a 4 pt board against his 2 pt board, and a lot to gain by playing a bit hitty.  I don't know why we didn't hit last time - and I don't know why we seem so afraid of doing something useful with this rotten roll! 

[close]

[diane]

I apologize to the Forum, last night I set GnuBG's dice generator to "diane twister" by mistake.

  Does anyone know how I turn this setting off, both in Gnu and Fibs?   

[NIHILIST]

Spoiler

We have a very stripped position which doesnt rate to get much better if we play " safe". I think this is a position where we take a small risk now, while he only has a 2 point board, to avoid a big risk later.

IMHO there are 2 plays worth considering 15-13, 8-7 and 15-13, 15-14.

The statistical likelihood is that we will get hit somewhere, so return shots are a consideration. If we play 15-14, 15-13 and he hits the blot on the 8 point with 2-1, we will have a non-entering 6 as a return.

Having said that, I slightly favor 15-13, 8-7.

[close]

Bob

[dorbel]

Spoiler

This is what the experts call TMP, Too Many Points. If you have seven made points then you have to break one in order to play next turn, unless of course you roll a double or can play all the roll with the spare, neither of which apply here. Try to avoid getting into a TMP position in the first place! Note too that Blue has only 13 checkers that can play and four others that are severely crippled because they can only play ones and twos. This combination of TMP and buried checkers is very weak. If you try and fudge this by breaking a point inboard and safetying the blot, you will have all the problems that you have now next turn, but worse, because you will have a weaker board and more checker burial.
At first sight the NIHo play doesn't appear to gain enough to justify the risk of starting a blot hitting contest, but in fact that risk isn't so great when you look closer. Blue has a stronger board and a good anchor and also gains more from increaing the gammon risk. Starting a fight now means that the buried checkers in Blue's board suddenly become useful rather than just sitting there! What this also means is that White is sometimes going to eschew (lovely word) the hit next turn, because it will be too risky for him. If we play 15/13, 8/7 will he hit with 6-4? Not sure, what about 6-2? Probably not. Some of the other hits look correct but distinctly dodgy, such as 6-3 and 4-2.
I like NIHo's imaginative and forward looking play, 15/13, 8/7 for me.

[close]

[diane]

Spoiler

I like NIHo's imaginative and forward looking play, 15/13, 8/7 for me.

[close]

Erm, ah_clem said that too, first    

I am glad to see this move is overtaking the safer, less useful suggestions 

[dorbel]

apologies for not acknowledging the earlier posts from ah clem and diane. They too are of course imaginative and forward looking.

[vikingblood80]

Spoiler

At first the blot on the 8 isn't really in danger. It only can be hit when rbk gives up his golden anchor.Since we ourselves have the best anchor too and we get quite some return shots (haven't counted them yet) and rbk is far behind in the race so he does not want to already give up his anchor now. -> No need to waste our 2 playing 8/6.

We want to keep our homeboard.

We want to keep the midpoint.

We want to keep our anchor.

So the most "useless" point is our 15. So the 2 goes 15/13 clearly.

Whats left for the ace? 15/14 or 8/7. Haven't decided yet. I hope this can be figured out by usual fine tuning looking at all possible rolls. To do this brain-work right now I'm too tired (1.00 a.m. right now) but my belly tells me 15/14. Tomorrow I'll make my final decision.

CU Viking

â,¬dit: Argh there will be no tomorrow. *hum..ok we cant duplicate any hitting numbers. If only the blot in our outer board is hit we can use the 6 to fire back wich we cant use for entering.

If we move 8/7 we only can hit back with 6es.(but may be rbk moves on or does a double hit)
If we move 15/14 we can hit back with 5es and 6es or cover it next turn may be. In case of a double hit we always can fire back with double 5es. I know there are more necessary arguments but I dont like to think any further.

I keep my blots more connected i.e. 6 pips apart instead of 8 points and I choose to play 15/14.

[close]

[diane]

This looks like it could be an interesting vote. Since I am away for the weekend, I set the voting period to three days this time. If anyone is in a hurry and the vote is clear, maybe diane would like to speed it up and do the next position, but perhaps it isn't necessary. At any rate, I hope there will be some good discussion on this, it's a very interesting position and dice roll! 

It most certainly has been an interesting position - and well worth waiting the extra time to listen to more views. 

[stog]

Spoiler

if rkb and his closest family were voting, which move would they prefer us to make? i think the bolder play, although i would now be tempted to change my vote from the safer play i advocated earlier!

[close]

[Whaat]

Spoiler

Guess its now15/13 8/7. Unfortunately, I still don't quite understand why...

Ho Hum...

The collective argument in favour of 15/13 8/7 (or its thematic equivalents) seems to be:

1) There are TMP --> Our stripped position isn't likely to get better next roll
2) Our board is one of our key - if not our greatest - strength
3) Our blots aren't really in that much danger because:
      a) RKB will eschew a hit because of his need to retain his anchor and...
      b) we have an anchor and RKB's board is weak.

We're certainly sufferring from TMP. Our outfield looks horrible. However, the three propositions that I don't particularly get is why are 'our stripped position isn't likely to get better', why RKB would rarely hit, and why our home board is so key.

Assuming that we had played safe this roll, almost all our subsequent rolls (34/36) will either break a point but only expose 1 blot (all 2,5, and 6s and a couple of others) or leave no shots at all (the doubles). Risking a double shot now would make sense to me if RKB's board was going to improve quickly (but it isn't), RKB would really eskew a hit, and/or if messing with our home board really is 'the last thing we want to do here'.

Is the home board really our 'biggest strength'? Its certainly better than RKB's, but it doesn't look priceless. For starters its got a gaping hole in the middle that's filled by our opponents anchor! This position looks like a mututal holding game, and I've always assumed that a racing lead was a player's biggest strength in these types of games? I could understand that we face diminishing returns as our race lead is so large (although I haven't read/heard such an argument before). I could also understand that the general rule for holding games doesn't apply - because in most holding games you don't actually end up getting hit - and contact seems more likley here. But in connection with my first objection, leaving two blots (as opposed to one next throw) seems to unnecessarily jeopardises our racing advantage - which still seems pretty important. 

I also (while I'm on my soap box) don't really see why RBK would often eschew (lovely a word as it is) a hit. 'The golden point' is not under pressure so leaving a blot there wouldn't be the end of the world. Dancing, although clearly bad, would be acceptable for a roll or so. Hitting costing us an average of just over 20 net pips (RKB gains 8 with his roll, we lose the rest re-entering) and with two blots about this means the race isn't entirely hopeless. Finally, if RBK doesn't hit now and the game enters a clear one way holding game (which appears the most likely outcome) then RBK isn't guaranteed another target, let alone another hit. I'm all for eschewing during a backgame, waiting to build up the home board and distribution while your opponent buries more checkers - but well, we've already buried our checkers and RKB's distribution is pretty nice...

Anyways, I'm sure the forum is right (it normally is...) but I'd really appreciate if someone could address my concerns. I feel I'm being forward looking, just guess not all that enlightened...

[close]

[vikingblood80]

Yes in generally 2-1 is not a good roll in this position so you have to choose the least evil.

Is the home board really our 'biggest strength'? Its certainly better than RKB's, but it doesn't look priceless. For starters its got a gaping hole in the middle that's filled by our opponents anchor!

YES it is! In such a situation the gaps are not much of interest, the number of made points is really more important. If rbk had only one straggler to bring back home then you are right and the gaps on 4 and 5 would be quite a bad thing.

We have four points and rbk just two. That is 56% for him to enter one checker and only 11% to enter two in one turn while we have 89% to enter one and 44% to enter two checkers in one turn. That's quite a difference and he needs to act more cautiously.

If he releases the anchor and got hit afterwards then he really can get in big gammon danger if he stays on the bar some time. During he's out with have quite some opportunities. Run our back men or flooding the outfield preparing for a late Blitz with loose hits,making or shifting points..long story short: all guns on the town hall. Depending on the situation and his homeboard then if we can afford to attack or not if we have enough ammo.

On the other hand if we are hit now you are right we loose ground in the race but that's only the short sighted look. In positions like these with many points in the outer board on both sides often the player wins who can stay back longer (has the better timing) cause the other player needs to open his last point and hitting him there now while his homeboard has adequate strength.So better to be hit now than later. If we are sent back now of course we loose some pips but then at least our game will be more balanced for future. That's a further look of how the game might develop.

[Whaat]

Spoiler

Thanks for the quick reply! Just so we’re on the same page, would I be right in summarising your argument as:

a)   The home board is useful if we are blitzing/attacking him. At present our home board is much more powerful. Losing one point would dramatically negate this strength. This attacking works best if he leaves his anchor.

b)   Flexibility is useful and getting hit will help our flexibility (as RKB’s board doesn’t pose any problems)

And well, I full heartedly agree. I just don’t see attacking as particularly relevant to our strategy at the moment, or see why are flexibility needs to be addressed this roll.

I certainly agree flexibility is a great thing to have. However, why do we have to have it this roll? The advantages of waiting would be that we’d only leave 1 blot next throw (this seems like a good thing when a double hit would practically eliminate our racing advantage). The only cost I can see , from not addressing flexibility this roll, is that we damage our board (RKB’s board will not improve any time soon). The significance of this obviously depends on our attacking threats â€" although, its not as if we have abandoned the 3 point for ever.

I think I could understand this reasoning if flexibility was our paramount concern. I’m not ruling it out, but I would want to hear a fuller case. If this is the case then getting hit is great. But then, if this were the case then we wouldn’t even want a racing lead. I understand how this can work when it comes to backgames â€" but here? â€" from a 30 pip lead? I still see this position as a mutual holding game where â€" although blots appear â€" they won’t normally be hit, and thus racing assets are our most significant assets.

I guess this might be because I don’t rate our attacking chances.

As I see it our attack will only really work when RKB breaks anchor, or leaves a large number of blots. I don’t see RKB being kind enough to do the latter (he has a nice flexible position) and I imagine RKB would only break anchor with a hit or a double.

A hit provides tempo, thus permitting only single hit returns. If he suffers a single hit, RKB has good chances to enter within two rolls and re-anchor. This is made more likely by our lack of ammo in the target zone.

RKB would only leave the 5 point with a double when the race is closer. This isn’t going to happen for a while (unless we get hit a lot or RKB rolls big…)

A strong board will obviously have secondary affects on RKB (i.e make RKB play more cautiously than he’d otherwise) but because we still have so much to do (i.e. bring all three points round), I don’t think dancing for a few throws would worry him that much. Gammon chances will remain low as long as he maintains his anchor or we lack ammo up front…

Personally, I’m pretty sure I’m wrong. Quite possibly badly wrong. But what really gets me is that I’m still not convinced where I’ve gone wrong…

So…currently, I think, my argument rests on four assumptions/ judgements. All of which are necessary to reach my decision. So if you could explain why I should dismiss one (or more of them) or even add to the list (!) then I’d be a ‘happy fibster’.

1) I characterise this as a mutual holding game
2) I believe that race advantages are more important than flexibility in most holding games, including this holding game
3)  I do not believe we have much potential, in the medium term, to attack
4)  I don’t believe that the of threat of attack is significant for RKB

[close]

[Zorba]

GnuBG 2-ply rollout:

Spoiler

    1. Rollout          15/13 8/7                    Eq.:  +0,0206
        50,15  13,41   0,17 -  49,85  11,87   1,58 CL  +0,1063 CF  +0,0206
      [  0,09   0,10   0,03 -   0,09   0,17   0,13 CL   0,0025 CF   0,0028]
    2. Rollout          15/14 15/13                  Eq.:  +0,0189 ( -0,0017)
        49,82  13,76   0,18 -  50,18  11,78   1,62 CL  +0,1057 CF  +0,0189
      [  0,09   0,10   0,01 -   0,09   0,16   0,13 CL   0,0025 CF   0,0028]
    3. Rollout          20/18 8/7                    Eq.:  -0,0378 ( -0,0584)
        48,25  14,21   0,16 -  51,75  16,28   2,33 CL  +0,0421 CF  -0,0378
      [  0,32   0,43   0,09 -   0,32   0,49   0,57 CL   0,0091 CF   0,0104]
    4. Rollout          15/14 8/6                    Eq.:  -0,0400 ( -0,0606)
        48,26  12,39   0,04 -  51,74  13,17   1,31 CL  +0,0429 CF  -0,0400
      [  0,30   0,39   0,91 -   0,30   0,57   0,30 CL   0,0092 CF   0,0099]
    5. Rollout          8/6 3/2                      Eq.:  -0,0870 ( -0,1076)
        47,35  10,89   0,21 -  52,65  14,24   1,22 CL  -0,0100 CF  -0,0870
      [  0,31   0,33   0,06 -   0,31   0,49   0,41 CL   0,0090 CF   0,0097]
    6. Rollout          8/6 2/1                      Eq.:  -0,1275 ( -0,1481)
        46,39  10,11   0,13 -  53,61  15,71   2,66 CL  -0,0530 CF  -0,1275
      [  0,34   0,31   0,04 -   0,34   0,60   0,56 CL   0,0095 CF   0,0108]

        Full cubeful rollout with var.redn.
        432-5184 games, Mersenne Twister dice gen. with seed 861171985 and quasi-random dice
        Play:  2-ply cubeful prune [world class]
        keep the first 0 0-ply moves and up to 12 more moves within equity 0,16
        Skip pruning for 1-ply moves.
        Cube: 2-ply cubeful prune [world class]

[close]