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Game 3, move 13: Forum 2-1

Started by Zorba, August 07, 2009, 02:12:59 AM

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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
The fascist's feelings of insecurity run so deep that he desperately needs a classification of some things as successful or superior and other things as failed or inferior. This also underlies the fascist's embracement of concepts like mental illness and IQ tests.  - R.J.V.

Luck is my main skill

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

Quote from: ah_clem on August 07, 2009, 02:52:22 AM
Aargh.  Who let diane roll the dice?

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

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?
Never give up on the things that make you smile

Zorba

I apologize to the Forum, last night I set GnuBG's dice generator to "diane twister" by mistake.
The fascist's feelings of insecurity run so deep that he desperately needs a classification of some things as successful or superior and other things as failed or inferior. This also underlies the fascist's embracement of concepts like mental illness and IQ tests.  - R.J.V.

Luck is my main skill

ah_clem

Quote from: diane on August 07, 2009, 07:35:28 AM

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

Quote from: lewscannon on August 07, 2009, 02:24:41 PMplease let's keep Diane away from the dice. Maybe we can give her a deck of cards to play with.

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

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!  :wacko:
[close]
Never give up on the things that make you smile

diane

Quote from: Zorba on August 07, 2009, 11:52:01 AM
I apologize to the Forum, last night I set GnuBG's dice generator to "diane twister" by mistake.

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

:lol:
Never give up on the things that make you smile

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
Robert J Ebbeler

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

Quote from: dorbel on August 09, 2009, 08:27:58 AM
Spoiler
I like NIHo's imaginative and forward looking play, 15/13, 8/7 for me.
[close]

Erm, ah_clem said that too, first  ;)  :laugh: :laugh:

I am glad to see this move is overtaking the safer, less useful suggestions  :thumbsup:
Never give up on the things that make you smile

dorbel

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

vikingblood80

#13
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]
Vikings had more fun at work

diane

Quote from: Zorba on August 07, 2009, 02:12:59 AM
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.  :thumbsup:
Never give up on the things that make you smile

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.

Quote from: Whaat on August 10, 2009, 11:00:53 AM
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.
Vikings had more fun at work

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]
The fascist's feelings of insecurity run so deep that he desperately needs a classification of some things as successful or superior and other things as failed or inferior. This also underlies the fascist's embracement of concepts like mental illness and IQ tests.  - R.J.V.

Luck is my main skill

dorbel

Spoiler
We should be grateful to whaat here, because he doesn't understand the need for the "dangerous" play and keeps right on trying to get it, thus affording a learning opportunity. As ever, why is more interesting than just knowing the answer.
If you make the "safe" play here, presumably 8/7, 3/2, it is safe, but only for this turn. Next turn our position will be worse than it is now because (a) our board will be weaker (and White's may be stronger) and (b) we have more burial, so fewer checkers that can be played. The six checkers on the low points will be able to play one 2 and three 1s between them, so all but dead. Note too that we will have burned the last safe 6. The remaining 6 checkers will somehow have to combine to make their way home, through an outfield crowded with White points.
If we make the "dangerous" play, probably 15/13, 8/7 but 15/14, 8/6 is an interesting alternate that I hadn't considered, we have to say "How much do we gain from this and how big is the risk?" What we gain is mostly that we have kept our board to prepare for the hitting that is almost inevitable now or later and we haven't buried any more checkers. We have also cleared a point and given ourself the chance to make an outfield point, pretty useful if we can. The risk is that we will be hit and lose our racing lead, but we do get return shots after most hits and I believe that White will, with some rolls, choose not to hit. He can't, with the cube on 2 and a 2-0 lead take too many gammon risks, because Blue stands to gain more from gammons than he does. Further, the usual gain from hitting, where he can ship a nasty cube after a fan doesn't apply here. He just isn't going to be redoubling this any time soon.
If you still don't get it, try setting up the position on a real board and play the risky play and the safe play say 50 times each and play the game to the end. Record your results. The results may or may not indicate which is the better play, it's too small a sample to be conclusive, but what will happen is that you will gain considerable understanding of "what happens next".
Incidentally I am quite confident that the "risky" play is the way to go, but it may well be that the "safe" play is not a very big mistake. Even if the safe play was a very good alternate, I would still choose the risky play. Why? Because the safe play means that rkb's next turn is trivially easy, whereas it will very often be difficult after the risky alternative.
[close]

vikingblood80

#21
Quote from: Whaat on August 10, 2009, 02:59:38 PM

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)


However, why do we have to have it this roll?

â€" although, its not as if we have abandoned the 3 point for ever.

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.


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


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


Hi again,

a) correct to give up the 3 point would weaken it dramatically

playing 8/6 3/2 is just too passive..it doesn't help us anyway..we only could wait rolling doubles next turn...we are in front in the race so we want to clear all our points safely and break as much contact as possible...the 15 is really useless for us.we want to clear it first. Playing the risky move with the spare on the mid we got a checker to play with or hitting back and still keeping the mid point...rbk has at least 2 checkers on the mid to play with 1 or 2 turns waiting for us not rolling doubles and leave a shot after the safe play. If we are forced already next turn after the safe play the blot on the 3 can turn out to be a disaster for us when some exchange hits will take place. It will be hard to cover and the 3rd checker on the 2 is just simply buried.The other 4 are not quite cause they are forming 2 points which help us.

All right the board helps us on attacks but it also helps us if we are able to hit one in the outfield. The chance is about 1/5 that he will stay on the bar 2 rounds.Even if he stays out just 1 turn that will help us may be clearing the next point or doing anything other useful.If he enters then at least he cant use his full roll only 4-4 and 5-5 will help him.

Well at least if he leaves 2 blots that could be enough for us to win..even gammon.

Don't underestimate the number of our returns cause he has so many points open in his homeboard.

As I mentioned rbk has two spares on the 13 and for some cases one on the 6 which he only wants to move past our anchor when he has to or to create a homeboard point. In general I would not call his position flexible.

1) true
2) depends on the amount of contact
3) yes not much cause most of our checkers are more behind, but at least some
4) at least its so significant that rbk cant afford to play an exchange of hits at the moment

we will see how the story goes  ;)

well at least something tells me that playing the deuce with 15/13 must be right (hopefully  :laugh:

Vikings had more fun at work

vikingblood80

See the RO posted by Zorba?

So its definitely best playing the 2 from 15 to 13.  :)
Vikings had more fun at work

lewscannon

I will eschew my previous vote to play it safe.

Whaat

Cheers for all the responses! All very helpful, and I will certainly try to manually roll this one out this evening.

I think I've almost certainly underestimated the amount of contact left in this game. But just a few final queries:

Paul, you say, that:

"8/7, 3/2... is safe, but only for this turn. Next turn our position will be worse than it is now because (a) our board will be weaker (and White's may be stronger) and (b) we have more burial, so fewer checkers that can be played."

I'm pretty sure I get the significance of a) now. However, I still unsure of the significance of b) in isolation from a). [I hope statement will make sense in a bit…]

Since there’s going to be plenty of contact now, our home board is effectively dead. So burying further doesn't really reduce the number of checkers in play (it is however a bad in relation to a).

Rightly or wrongly, I don't value any pair of our outfield points more than any other pair. If so, I would have thought that breaking any point next turn would have provided us with similar levels of flexibility as breaking a point this turn. [And as a gain â€" if you counting our rolls for the next throw, almost all of them would leave only 1 blot (as opposed to 2). For example 6s would either allow us to clear one of our points (including our anchor) or let midpoint jump home.]

If we don't have key outfield points, it appears to me (now) that the then costs just reduce to the relative damage to our home board â€" and that these costs over-power the gains from saving a blot. So if are outfield points are all of equal value â€" then I completely see where I went wrong!

However, if our outfield points are of differing value â€" and the 20 and mid points are more valuable then the 15 â€" then our position next turn (after playing safe) is much less flexible then I thought. If so, then we’ve got to clear the 15 point now while we can.

I hope this rant makes it a bit more understandably why I’m not letting this position go so quickly. Basically, if some particularly combination of outfield points are significantly more valuable then others, then I’ve completely mis-understood what or why I’m craving flexibility. And if that’s the case I going to need to roll this one our more than 50 times…

vikingblood80

Quote from: Whaat on August 10, 2009, 06:22:57 PM
Rightly or wrongly, I don't value any pair of our outfield points more than any other pair.

However, if our outfield points are of differing value â€" and the 20 and mid points are more valuable then the 15

At first one comment: Yes its kind of a mutual holding game, but rbk holds us more than we hold him.

2 simple questions, 2 simple final quick answers from me:

Why do have outfield points a high value for us? Because we need some (1 or 2 are may be enough) landing spots to bring our men home. A checker can't go directly from the mid to our home. (Additional : More points would harm our play and may be we would get in (big?) trouble clearing these points. I think the 8 or 9 point would work best for that purpose.)

Why do our 15 point have the least value? A point controls the range within 6 pips apart.Any other points within that range are only useful for blocking. We don't wanna block rbk instead we wanna get home.So this point is our pain in the neck and we want to get rid of it first. Its just as simple as that.

Cheers Viking!
Vikings had more fun at work

Whaat


Zorba

Good explanations here, I would just like to add the importance of timing here. In a one-sided holding game, with f.i. checkers on the midpoint and in the outfield to bring home against a high anchor, being ahead in the race is usually much to your advantage. There are very good chances to bring it home safely and very little chance to get beaten in the race somewhere, even if opponent rolls a high double.

In a mutual holding game, ahead in the race is a mixed blessing. It is usually still an advantage, but much less so. The problem is that being ahead in the race usually means you have worse timing than your opponent. That means that at some point, you will be forced to break useful points because you're running out of plays, while your opponent still can move some spares around, etc. This is where your opponent gets his chances to hit you, and turn the game around. Of course, a lot depends on how strong your opponent's offense is by that time.

In this particular position, we are far ahead in the race: 33 pips effectively, with 125 to go. Since we also made three deep points and an extra outfield point, our timing here is pretty bad. If we don't do anything about it, we are likely to run into trouble later, when rkb is better prepared to profit from it, and we are in worse shape because of messing up our board, or lacking flexibility, etc. "Waiting for our eventual doubles" to solve the problem is unlikely to work here, as we simple don't have enough rolls left and may in fact need two sets of doubles to get out of trouble completely!

The best way to improve your timing is usually to move your backmen up. Lacking that, breaking up a point to create to spares is a good alternative. Getting hit obviously also improves your timing, as long as the backmen aren't severely blocked. Here, we are so far ahead in the race that getting hit is not such a problem, race-wise. That is an additional reason to break the 15pt: we can afford to lose some in the race.

Another important aspect of this position is that several numbers are blocked for us (mostly threes and ones), making certain rolls play even more awkwardly. This increases the risk of having bad timing. We could be forced to break a point later with a very awkward roll, and "lucky doubles" might be blocked and turn into a nightmare (f.i. 3-3).

Last but not least, leaving two blots here is not nearly as risky as it might seem, because many hits are uncomfortable for rkb, breaking his anchor or some other point, and thus giving us plenty of return-shots. With our much stronger board and the matchscore penalizing gammon losses for rkb more than usual, this is a very serious consideration. rkb's actual 4-1 was a case in point: it turns out to be a blunder to hit with that roll.

So the conclusion is that we have bad timing here, but a huge racing advantage, a strong anchor and a much stronger board. We improve our timing with 15/13 8/7 with not that much risk. The safe play worsens our timing and messes up our board, which won't be easy to remake and buries a checker in a position where we are already inflexible.
The fascist's feelings of insecurity run so deep that he desperately needs a classification of some things as successful or superior and other things as failed or inferior. This also underlies the fascist's embracement of concepts like mental illness and IQ tests.  - R.J.V.

Luck is my main skill

Whaat



Hi Zorba. Thanks for the input, and many of the new points you raise.

However, I feel (and I’m going out on a limb here!) that the stress on flexibility and timing isn’t helpful to understanding the choice of plays â€" as opposed to the position. 

I think this is what I was trying to grapple with yesterday…

(- Btw, I understand timing â€" from your post and books â€" as either synonymous with flexibility or as means of measuring flexibility, and not really an issue in its own right. But please correct me if I’m wrong - )

“If we don't do anything about it, we are likely to run into trouble later, when rkb is better prepared to profit from it, and we are in worse shape because of messing up our board, or lacking flexibility, etc.”

“The best way to improve your timing is usually to move your backmen up. Lacking that, breaking up a point to create to spares is a good alternative.”


And for what it’s worth, I completely agree. But we could have done something about our timing and flexibility next turn. And in the absence of doubles we basically had to!

As such our gains in timing and flexibility should be seen as gains relative to our next throw (not absolute gains). With the exception of those double 3s you spotted, I don’t see there being much gain in having flexibility next turn (Rkb’s new position hasn’t made us need any more flexibility) as opposed to the turn after next.

So our decision process should focus more heavily on the other costs and benefits. And given the points raised by everyone already, the balance is pretty clear.

The benefits of the safe play are no blots (for this turn), and only 1 blot likely next turn. The costs are that we break our board. In contrast our gains after the bold play are that we get to break our least useful outfield point and we get to keep our home board intact. The costs are two blots this turn.

The gains from the safe play aren’t that impressive â€" as RKB quite often won’t hit. The costs are significant because of the amount of contact left and the affect the play has on rkb’s moments.

For the bold play, I suspect that breaking the 15 point (as opposed to a different point) wasn’t the main driver for the difference in equity. However, the benefits of keeping our home board are clear enough. In turn the costs are also slight. 

Thus â€" to me - the flexibility and timing consideration seem to wash out over the course of the two throws. However, the other costs and benefits are clearly stacked in favour of making the bold play now.

So, yeah, any chance I'm getting warm yet?!