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Position # 56

Started by PersianLord, March 26, 2009, 07:54:28 PM

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PersianLord

Position information:

Pip-count: Red 121-121 White
Score:       Red    0-0    White
Match:                5-pointer

Red to play 6-6

Spoiler
Position ID: OG8HAwTKzowHAA Match ID: cAm7AAAAAAAA
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The leftist's feelings of inferiority run so deep that he cannot tolerate any classification of some things as successful or superior and other things as failed or inferior. This also underlies the rejection by many leftists of the concept of mental illness and of the utility of IQ tests.  - T.K

stog

Spoiler
i like 13/7-10/4*(2)-8/2 because of the potential if i don't get hit
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PersianLord

Spoiler
It seems that stog is as aggressive as me. I played 13/7-10/4*(2)-8/2, hoping to take the sh** out of my opponent by winning a tasty gammon. But GNUBG favors the cowardly move of  13/7(4) and considers my (and stog's) move as a serious blunder (0.289). Here's GNUBG's 2-ply analysis:

    1. Cubeful 2-ply    13/7(4)                      Eq.:  +0.983
        82.3%   6.3%   0.0% -  17.7%   0.4%   0.0%

       
    2. Cubeful 2-ply    13/7(2) 8/2(2)               Eq.:  +0.954 ( -0.029)
        75.1%  13.6%   0.1% -  24.9%   2.5%   0.1%
       
    3. Cubeful 2-ply    13/1(2)                      Eq.:  +0.910 ( -0.073)
        73.2%  13.3%   0.1% -  26.8%   3.0%   0.1%
       
    4. Cubeful 2-ply    13/7(2) 10/4*(2)             Eq.:  +0.709 ( -0.273)
        70.7%  24.7%   0.3% -  29.3%   7.5%   0.2%
     
    5. Cubeful 2-ply    13/7 10/4*(2) 8/2            Eq.:  +0.693 ( -0.289)
        71.2%  31.6%   0.3% -  28.8%   6.9%   0.3%

       
As you can see, GNUBG's move definitely wins much more simple wins than my move (82.3% versus 71.2%). Well, if it was a DMP game, I would have agreed with the bot, but it's the 1st game of a 5-pt match with the cube at center, so why not going for a tasty gammon?

GNUBG's move wins much less gammons (6.3% or 6.3/82.3% ?) than my move (31.6% or 31.6/71.2% ?). I think we can take the risk and play bold here.

Regards

[close]
The leftist's feelings of inferiority run so deep that he cannot tolerate any classification of some things as successful or superior and other things as failed or inferior. This also underlies the rejection by many leftists of the concept of mental illness and of the utility of IQ tests.  - T.K

dorbel

Spoiler
13/7(4). Cash and move on. Make the risky play and go for an undoubled gammon? One for dreamers.
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NIHILIST

Robert J Ebbeler

stog

thx :) i wonder if i'll learn my lesson! good problem thx all

NIHILIST

It's a pretty easy lesson. Regardless of how you play it, youre up 24 pips after the roll. If you dont hit and he rolls 5-5 you might feel a bit silly, but thats 1 number in 36 whereas if you hit, he has at least 13 return shots at the blot on the 3 point and maybe more depending on how you play the 4th 6. Playing 13-7 4 times lets you claim an easy point early in the match.

Now, let's assume you trail in the match 4-3 to 5, Crawford. You can certainly make a much stronger case for hitting since a gammon wins the match for you. I still think I'd play it 13-7 (4) over the board.

As a final note, and to illustrate the difference between match and money play, in a money game playing 13-7 (4) is automatic since the cube is in the middle and gammons arent an issue.


Bob
Robert J Ebbeler

blitzxz

Spoiler
Clear cash out as said. But I started thinking is there any score where bringing home 4 from mid is not correct. And I don't think so. If it's double match point running for home is still clear match winner (no reason to give shots for nothing). And if it's 2-away leading you propably should still head for cash out because gammon chances are so small with only one checker behind.
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socksey

OK, I fess up and say I played the blunder too!   :yes:  I see the logic in playing the safer way, tho, and maybe I'll remember it.   :laugh:

Thanks for all the good comments, guys!   ;)

socksey



"In reality, the Holy Land doesn't need walls, but bridges." - Pope John Paul II, commenting on Israel's separation wall, quoted in The Washington Post

lewscannon

If sox is brave enough to say that she played the blunder, I have to say I played it too. I tend to play over aggressively at times and moving the 4 pieces is a much smarter move. There. I feel better now.

lews

Tomawaky

Spoiler
13/7(4) and certainly turn the cube next turn
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Tomawaky "I feel good da da da da da da da.........i knew that i would now........."

playBunny

Spoiler

The two contenders for me were the hit and bringing the midpoint down wholesale. The hit (10/4*(2) 8/2 13/7 has got the downside of return hits whereas the 13/7(4) makes a safe broken 5-prime with a pip lead of 24. After that only a 5-5 is going to escape the opponent's backrunner and level the race to a sufficient degree for the opponent to breathe a sigh of relief.

After 13/7(4) then, barring a 5 to escape, that backrunner is a sheep with many wolves slavering over the prospects. The blots on 2 and 3 make hitting a bit awkward but there's plenty of scope. Time is on our side.

Thus the hit gets rejected and we bring the midfield home.
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dorbel

PlayBunny misses the point, which is that unless White rolls 6-6 or 5-5, the game will end with a cube turn, so the wolf can slaver all that he likes, but he isn't going to be attacking much! After 5-5, Red won't be good enough to double. After 6-6, he will have a double though, because the last White checker will still be blocked and Red will have some attacking and racing chances as well of course. White needs to play 6-6 well though and that probably means making her 1 and 2pts, even though it wastes pips. Doing that will give her a four point board and thus deter Red from the more extreme blitz plans.

dorbel

This position, from a five point match today, illustrates a similar theme, except that the cube has already been turned. Can you find Black's best play for 3-3?
Black leads 2-0 to 5.

NIHILIST

13-10 (2), 9-6 (2). Same theme except gammons are significant for both players. Black is hugely ahead in the race, just needs to clear safely to go 4-0, Crawford.

While 8-5 (3), 5-2 is tempting, it farts squarely in the face of clearing black's midpoint, which is his biggest obstacle. Black doesn't want a hitting contest here, he just wants to win quietly.

Bob
Robert J Ebbeler

diane

Spoiler
Whilst I hate to be in agreement with 'him' about anything, there really isn't anything else to do - 13-10 (2), 9-6 (2).  When so far ahead - why on earth would you risk getting stuck at the back of that white barricade....Stay safe and in front.
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Never give up on the things that make you smile

blitzxz

When you're leading run safely to home and when you're trailing fight for the last man. :) Simple and common rule which is rarely wrong in basic holding and running games.

dorbel

yes this is of course (!!) the best play and anything else is a big blunder. My opponent actually played the interesting 8/5*/2, 9/3, an "attack with not much immediate risk" sort of play which I didn't consider at the time, but it doesn't deal with the biggest problem which is as NIHILIST points out, the clearing of the midpoint.

playBunny

Quote from: dorbel on March 29, 2009, 11:41:34 AM
PlayBunny misses the point, which is that unless White rolls 6-6 or 5-5, the game will end with a cube turn ...

Well, you can call it missing the point if you like but I think of it as focusing on the checkerplay, which is my forte. I make no claim to be an expert in the cube at this time and thus prefer to talk less about it.

The post that I made is good checker play logic and would be useful to others who tend to underplay the cube, as well as in a 1-pointer where checker play is the only consideration.

ah_clem

Safe play or bold play?

Red is ahead in the race (or will be once the 66 is played.)
Red has no checkers back.
Red faces no real threats.

All point to a safe play (e.g. 13-7(4)) rather than a risky play (i.e. putting a white checker on the roof and leaving a shot.


Zorba

Quote from: PersianLord on March 26, 2009, 08:29:47 PM
Spoiler
It seems that stog is as aggressive as me. I played 13/7-10/4*(2)-8/2, hoping to take the sh** out of my opponent by winning a tasty gammon. But GNUBG favors the cowardly move of  13/7(4) and considers my (and stog's) move as a serious blunder (0.289). Here's GNUBG's 2-ply analysis:

    1. Cubeful 2-ply    13/7(4)                      Eq.:  +0.983
        82.3%   6.3%   0.0% -  17.7%   0.4%   0.0%

...       
    5. Cubeful 2-ply    13/7 10/4*(2) 8/2            Eq.:  +0.693 ( -0.289)
        71.2%  31.6%   0.3% -  28.8%   6.9%   0.3%

       
As you can see, GNUBG's move definitely wins much more simple wins than my move (82.3% versus 71.2%). Well, if it was a DMP game, I would have agreed with the bot, but it's the 1st game of a 5-pt match with the cube at center, so why not going for a tasty gammon?

GNUBG's move wins much less gammons (6.3% or 6.3/82.3% ?) than my move (31.6% or 31.6/71.2% ?). I think we can take the risk and play bold here.

Regards

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Spoiler
So, the safe play wins 11.1% more single games, equivalent to 0.222 equity in a cubeless money game.
Your bold play wins 25.3% more gammons, equivalent to 0.253 equity in a cubeless money game.

If GNUBG's estimates are correct, the bold play is slightly better in a cubeless money game.

The bold play might also be better if you had already doubled, although that is not clear right away. The extra single wins for opponent after the bold play, will increase his recube vig compared to after the quiet 13/7(4). I.e. opponent will get to offer more/stronger recubes after your bold play, because his chances of turning it around will be higher. The safe play might therefore be better even with oppponent holding a 2-cube, I think (interesting to check this with GNUBG).

At some scores and cube values where gammons are very valuable, the bold play will be best, but mostly when opponent's already been cubed before this play.

In this position however, the cube hasn't been turned, but you'll have great chances to cube next turn. If you go for the bold play and it works, it's probably a big pass, and therefore overkill. If the bold play gets hit back, you're in trouble. The safe play will nearly always give you a cash next turn and pretty efficient cube use.

So, this is an example of a checker play that is influenced by the cube (position) and where efficiency with regards to cube play is important.
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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