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Bundalongadorbel

Started by dorbel, June 23, 2015, 12:16:25 PM

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dorbel

This is going to be a thread, to which I hope to contribute every day, featuring an interesting match position. As soon as I can figure out how to show the position, I'll be right back!

dorbel

And here is the position. White to play 5-3, score 0-0 to 13. White can make his 3pt or he can hit loose. Which is right?

dorbel

White to play 5-3. 13/5* is right and 8/3, 5/3 is a small error. The idea is to take away half of Black's next roll and of course a lot of the equity swing comes from turning Black's 6-6 from best roll to worst roll. Black is a favourite to hit back, but a lot of the rolls that hit would play well anyway, so it isn't a disaster. When Black can't hit, White is on roll with his 5pt slotted, always nice.
Hitting is also correct at dmp and gammongo and by a small margin at gammonsave as well. However, a beginner/intermediate playing an expert might do quite well to choose the simpler 8/3, 5/3, but beginners that know how to vary their play for stronger opponent's are rare birds indeed.
Over the board, I chose to hit, but I already knew it was right, so no thought required.

Here's one I got wrong. White to play 4-3. The score is still 0-0.


dorbel

Yesterday's position looks as if there isn't much happening, but it does illustrate an important theme. It's important for White to get he blot on his 24pt into play, so that he can hit from there (if he gets the chance) without breaking his anchor. So 24/20 is the important bit and then you can choose a three. I selected the second best play, 11/8, but it doesn't apply much pressure and 6/3* is correct. My play is right at gammonsave, which implies that I am not playing aggressively enough. "When in doubt, hit" remains one of bg's enduring guidelines.

Later in the game, we got to this next position, where White has to think about cubing. It's a monster pass of course, but is it too good? We'll see tomorrow.

dorbel

The right answer for yesterday is actually double/pass, with playing on having an equity of .982 compared to the equity of 1.0 for cashing. The question of whether to cash this sort of position or play on is always hard to answer. If I'm not sure I usually double anyway, putting a point on the score sheet that I don't have to earn with good play, but I guessed that this was much too good, wrongly. This is a reference position if you like to keep them, one where the equity is almost the same regardless of what you do.
Things went well for a while, but then Black managed to hit back during a fight for White's 5pt. With both sides having a man on the bar, what is the right cube action here?

socksey

White has a far better board and easy out so I would go with a cube.



dorbel

#6
White should indeed double from the bar, even entering without hitting is a market loser if Black dances and for Black, this is a very big pass. Black actually wins this about one game in 3, but loses a huge 43% gammons. In the match I cashed and led 1-0 to 13.
Boards too dark and hard to see? Here's a new one.
In game two, Red rolled 6-4 and made her 2pt. Once upon a time this was the play that marked you as a fish, but times have changed and this is now correct at gammongo and other scores where the player trails. How should White respond with his 3-2?

dorbel

So, White to play 3-2. The temptation is to split at the back, working towards securing a high anchor, but 13/10, 13/11 is best by a very small margin. Because Red has made her 2pt, it's going to be very hard for her to make a containing blockade. The 2pt and the 8pt can't be part of the same prime, so no hurry for White to split. Splitting actually plays into Red's hands, as it gives her targets to attack and blitz, where her 2pt will be useful.
I played 24/21, 13/11, but that isn't even the best split, as it moves to a point that Red would prefer as a target. 24/22, 13/10 is the best split. The match play is a small mistake, -0.028ppg.
The rest of game 2 proceeded along uninteresting lines and I eventually cashed to lead 2-0 to 13.
In game 3 we arrived at the position below, White on roll and contemplating a cube. What's the correct cube action for both sides here?


NIHILIST

This thread is like the sound of one hand clapping.

Bob
Robert J Ebbeler

stog

the thread or your post Nihole?

they are interesting positions and thoughtful commentaries

why not contribute some of your own instead of vacuous criticism

TimDugan

My play would be a double/take ... anyone else?
"A committee of two people is most effective when one doesn't show up." -Phil Simborg

NIHILIST

Stog writes 
Quotethey are interesting positions and thoughtful commentaries

why not contribute some of your own instead of vacuous criticism

They may be interesting positions, but I don't see much in the way of commentary except that of the author. I only can hope he doesn't get bruised patting himself on the back.

I have contributed what I consider to be thoughtful commentaries on many occasions which have often been greeted by vacuous criticism, some of it your own. I don't recall you ever inserting yourself to chastise any of my critics.

No harm, no foul, or, in the words of a former client, NEVER EXPLAIN, NEVER COMPLAIN.

BTW, if I had referred to dorbel as DIMBELL or DORKBEL, no doubt you would have censored that. I guess you feel that only you can use derogatory names without fear of censorship. It's a cheap shot which in my opinion demonstrates your own brand of hypocrisy and is unworthy of anyone claiming to be an impartial moderator of debate and discussion.

Bob
Robert J Ebbeler

PersianLord

#12
Quote from: NIHILIST on June 30, 2015, 05:29:52 AM
StogNihole writes  
They may be interesting positions, but I don't see much in the way of commentary except that of the author. I only can hope he doesn't get bruised patting himself on the back.

I have contributed what I consider to be thoughtful commentaries on many occasions which have often been greeted by vacuous criticism, some of it your own. I don't recall you ever inserting yourself to chastise any of my critics.

No harm, no foul, or, in the words of a former client, NEVER EXPLAIN, NEVER COMPLAIN.

BTW, if I had referred to dorbel as DIMBELL or DORKBEL, no doubt you would have censored that. I guess you feel that only you can use derogatory names without fear of censorship. It's a cheap shot which in my opinion demonstrates your own brand of hypocrisy and is unworthy of anyone claiming to be an impartial moderator of debate and discussion.

Bob

We salute you Leviathan.

-------

stog: this user is now banned
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

Nihole writes

QuoteI guess you feel that only you can use derogatory names without fear of censorship. It's a cheap shot which in my opinion demonstrates your own brand of hypocrisy and is unworthy of anyone claiming to be an impartial moderator of debate and discussion.

1/ I am not a Moderator I run this site and 2/ I am not impartial

and for someone who dishes out sh** you seem to be extremely thin skinned when some of it splashes on you and 3/ you are banned reason -- Negativity and trying my time/patience.

OLIN

The theme of whether to cash this sort of position or play on is for each situation difficult to answer. In the event that I don't know I regularly twofold at any rate, putting a point on the score sheet that I don't have to win with incredible play, yet.