i declined the offer to double in this game

any opinions about my drop?
(and any opinions on the offer of the double at that position?)

playBunny: lol! i never noticed that box :)
thanks :)

Hrqls: how can i search through more than 10 posts ?

There's a search box to the right of the message box. Stick in a keyword - something that you're likely to have said and hit the button. (In fact it takes regular expressions if you want to get fancy - and that probably really confuses people who use RE characters without realising!)

playBunny: lol ... remember what i said ?? i dont even know what i am about to say 10 seconds before it rolls out of my fingers ;)

how can i search through more than 10 posts ?

Hrqls: It might be easier to remember what you said here about it and use the search box.

playBunny: hmm i had a nice game in which my opponent had a lot of pieces off already and me trapped .. but i still won the game .. i think i showed it on here .. but i dont remember with whom i played the game or when .. i will see if i can find it back :)

Does anyone have any particularly memorable games - because of something spectacular, or very unusual, or that seems like a good example of some strategy or tactic. Examples of the former would include incredible dice, games where all of your blots get hit but none of your opponent's. Examples of the latter would include blotfests (early fights which result in a Nackgammon-type situation), blitzes, prime building, back games.

I'm going to add a section to the Backgammon Links for such games. The more the merrier.

ColonelCrockett: LOLOL

playBunny: errr . . . hmmm . . . isn't backgammon great. lol ;)

ColonelCrockett: OOK? Are you the librarian at Unseen University?


[Now we're waaaay off topic and into Discworld, lolol]

Eriisa: ooookkkk ;)

playBunny: oh, yes! ;) I've been a very aggressive little vampire! (I've brought the board to yet another subject, for shame, lol)

ColonelCrockett: In other words.... you missed all the fun!

ColonelCrockett: Lolol. Where've you been when we needed your guidance? Off on your own blood sucking quest, no doubt!

[Not an insult, our Colonel is a vampire.]

playBunny + Hrqls: I leave for one day and this board gets off track . . . who knew that a backgammon board would get into hypothetical geneto-biology. ;)

Hrqls: Aye, there's a big differences in pheromones (but I don't think it's that for the mozzies either as I'm the target amongst people that I know).

playBunny: lol! isnt there a difference in smell between male and female ? i should ask the mosquitoes, they always pick my gf first :)
(but she isnt blonde ... so maybe its not the sexe but the color ?)

i know .. i know ...

Hrqls: No carry on sweating and make sure you bottle it. I know a guy who can get $$$ for refined blond sweat. ;-)

(Sue, you can delete this one once we've finished chuckling )

playBunny: *phew* so i can stop sweating now ;)

Hrqls: No problem. I'm pretty sure I speak for grenv as well in saying that that's always been a consideration when we answer a question. :-)

playBunny & grenv: thanks.
just tell me if i ask a question too soon and i will postpone it until the game has been finished :)

the best way to learn is from examples i think, thats why i keep asking about positions which came up in games i played :)

DragonKing: Yes the stratergies are very different. Though the dice will decide if you play an attacking game or defensive. Best way to find out is to play, you'll soon notice different ways to play.

If the rules to Backgammon and Nackgammon are the same- I assume that the correct strategy for Nackgammon is slightly different from a godd Backgammon game- because of the two extra chequers? Are there any general principles for Nackgammon that differ from Backgammon. (I finally noticed I can set GNU to play Nackgammon.)

grenv: however I would err on the side of caution if you aren't sure.

Yep

playBunny: I agree it depends on the position, and what knowledge you gain, however I would err on the side of caution if you aren't sure.

pentejr Yes, the %age changes slightly depending on the match score, but not as much as you might think. You also have to account for gammons either way so a simple percentage is not useful until both players have borne off.

What you need to do is work out the chance of winning for each match score (there are tables) and figure it out from there.

So in a 9 point match, ignoring gammons, if I refuse my chance of winning from 0-1 is about 44%.

If I take the double I will either be at 0-2 or 2-0. The chance of winning from 0-2 is about 37% and, conversely, from 2-0 is about 63%.

So if my chance of winning the first game are currently x, then my chances of winning the match if I take are .37(1-x)+.63x = .37+26x

So to equalize to teh 44% chance if I drop, then .44 = .37+.26x
.26x = .07
x = .07 / .26
x = about 27%

Which, as you said, is a little more than 25%

:)

Hrqls: grenv said "If you analyze immediately after a move it may give you insight into the position that you wouldn't otherwise have".

That wouldn't apply to a cube decision unless recubing wa sin the air but woudl to chequer play.

With chequer play it depends on the move and the stage in the game. If it was about whether it was wise to risk putting a blot somewhere and that blot's been hit taking the game into a new phase then there is no danger of gaining inappropriate knowledge about the current position - too much has changed.

As an example of a case where I wouldn't give advice, say you are trailing badly and have hit a last-minute blot and are trying to contain it. I wouldn't discuss how you'd lay your backrunner net down or build your forward blockade on a particular move because the advice would be strategic and cover that whole phase. On the other hand I was happy to discuss Czuch's game just now because there was nothing he could gain from anything I said.

so its best for me to wait until a game has finished before i bring a position here to discuss ? even though i already made my move ?

i will wait a bit longer with my next questions then :)

I once read in a backgammon book (I think it was Robertie--I haven't read that many) that the break even point for taking a double should be 25%. If you win 25% of the doubles you accept, this person wrote, over the long run, you won't be behind any more points than if you dropped every game for single stakes (for instance, over the course of four such games, you'll be down 6-2 instead of 4-0, etc.).

This reasoning seems to me to miss one crucial factor--volatility. In a nutshell, I would rather be down 4-0 than 6-2 in, say, a 9 point match because 6-2 puts me closer to losing. Consequently, I think you need to adjust that 25% up--you need more than that to accept, and you need less than 75% to double. But I don't know how much to adjust that. I guess it would depend on the count in the match, length of the match, etc.

Thoughts on this?

I think you shouldn't analyze until after the game (not the match, just the current game). If you analyze immediately after a move it may give you insight into the position that you wouldn't otherwise have that could be used next turn.

Pythagoras: Thats a lot of work for such poor sarcasm ;)~

It does bring up a good point though.... when is it okay for advise?

playBunny: Czuch: "Is it against the rules here to have a program assess a situation to help determine the probability to get a gammon or if a double should be offered?"

For sure. You should only analyse a chequer play or cube decision, after you've made it. Same with discussing it here. "

No! About the first case: You should NOT analyse a chequer play or cube decision, after you've made it.

Why? Because you may have an exact position later against another opponent or the same one! So you would gain inappropriate knowledge that comes from a computer! Cheating!
Also you should wait all games here to finish before analysing with a computer anything! Why? Because you may have a position you analysed so you will gain that knowledge and play according to computer's analysis.....
So in short: We should never use computer for analysing anything until we stop playing here.....

In the second case: "Same with discussing it here."
Again another person may meet the exact position with what you had and shown with your analysis so he would take advantage of it. So no more analysis here until all games finish. In 15-20 years i guess.....

Czuch: Lol. I was ahead of you. I took a guess that it was a current game so I've got the whole thing staring at me. Oh dear, oh dear. I don't think it's cheating to say don't redouble!

But the double that was offered .. you were right to snap it up - it was way to early. All your opponent had was an anchor giving 60% win including 15% gammons. Not enough by far. That 4-4 was handy but still not enough. Had the double come after the 4-4 it would still have been too early. And after hitting you and you dancing? Not as bad but not time to double. The 5-5 was good. Chances went up to 80% but you got in and hit back. Bad time to double then as well.

But then you got hit again and danced. But then it was beyond doubling! Time to get out the frying pan and chase the sizzle.

playBunny: okay, back to your job of doing what I should bedoing if I had a computer! LOL, Thanks!

playBunny: *nod* thats what i tell myself all the as well and why i bear off as many as i can ... the only really bad thing that can happen is for me to roll a double of an empty spot and therefore missing 2 bear offs while i maybe could have prevented that if i had not beared off as many as possible ... but i have no example of such a bad thing (yet :))

i began to wonder some time ago when i beared off as many as possible on a roll on dailygammon, and the site didnt continue with a predicted next move .. so i assumed what i did wasnt the best move (according to the sites engine)

Czuch: The best play would have been to put a link in your message.

Hrqls: If you miss bearing off a piece with the current roll, why would you be doing so? To save the risk of being forced to miss on bearing off at a later stage. But that's voluntarily falling behind because of something that's only a possibility.

There are times when you shouldn't bear off as much as you can. Unfortunately it's been rare enough for me that I can't think of any examples and I still have to ask GnuBg to see whether I chose correctly.

Hrqls: am not an expert, but my opinion is that you have to take as many off now as possible, and hope for a double 6s next turn, as double 6s is as likeley as any other roll you may get.

Okay, I was offered a double here and accepted it..... what was the best play and why? (btw....his next roll of double 4s was not availqable for my decision) (nor his double 5s on the roll after that!)

http://brainking.com/en/ShowGame?g=1411482

is it always wise to bear off as many pieces as possible in the end game ?

for example in this game .. i roll double 2 and beared (bore?) off 3 pieces ... but this leaves me with 3 empty positions and a pile on 6 ... should i have beared off only 1 or 2 pieces and reduce the pile on 6 instead ?

Hrqls: No, that was my double 2 that I did n ot use....

Czuch Chuckers: i meant at the end of the game

she just rolled a double 2 and could bear all her men off except 1

you had only 4 men in your home, so either a double 4,5 or double 6 would win you the game ... that still was a chance of 1/12 to win .. but you resigned and threw away that chance .... we will never know if your next roll would have been a high double though :)

Czuch: "Is it against the rules here to have a program assess a situation to help determine the probability to get a gammon or if a double should be offered?"

For sure. You should only analyse a chequer play or cube decision, after you've made it. Same with discussing it here.

"It is a good example tha a back game can win, but that will only happen once every 25 situations or so, although that number seems too high to me."

That 1/25 is much too low. Have a look at those numbers again. Sue had a 1/10 chance even when you were down to your last 6 men. With a double-anchor back game your chances can be as high as 30% and is why you should be hesitant about doubling if you're winning and ready for the cube if you're the one playing the back game.

Is it against the rules here to have a program assess a situation to help determine the probability to get a gammon or if a double should be offered?

Hrqls: You cant resign without seeing your next roll.... it was double twos, I think! That game should have been a gammon for me and we should be tied at 4 each, but NOOOOOOOOOOOOO!!!!!

It is a good example tha a back game can win, but that will only happen once every 25 situations or so, although that number seems too high to me.

Czuch Chuckers: why did you resign in the last move ? you could have rolled a high double and still win

that game was a nice example of how a backgame can win :)

Czuch Chuckers: you know, internet access is quite cheap these days. If you really like using your TV as a "computer" monitor for internet surfing, on most modern TVs, you can run a coaxial cable from your hard drive to the TV to make it your monitor, that would be a natural transition for you WEBTV users. With that capability and WEBTV's costs, I really can't see it having any advantages anymore.

Czuch: Heh heh. Forget the Backgammon, I just want your money!

playBunny: HAHA LOL... you already refused all of my game invitations!

Czuch: Sorry to hear that. $$$$$$ Where can I come and play you.

playBunny: Thank you! WebTV doesnt have much ability...
This type of game is a good example of how I plummeted from 13th to where I am today.... not doing much better in my poker games either! LOL!