Czuch:


Just after Sue's 3-3 you had a 91% chance.
When you then had to leave a blot it went down to 84.5%.
When she hit the blot it went down to 60.3%.
At the point just before Sue started bearing off it was back up to 70.9%.
After her first bearoff and a gap opened it was 71.6%.
After you got your man back in it was 74.3%.
When she hit you again it dropped to 66.4%.
By the time you'd finished dancing and got back in it was a mere 23.5%.

I a so depressed!
Can someone please put this position into on of your programs and tell me the odds of me losing this game? Also the odds of me getting a gammon? And winning without a gammon?

I hate this game!!!!!

http://brainking.com/en/ArchivedGame?g=1405138&i=50

Pedro Martínez: Even without looking the games a score of 20 won games out of 20 games played, in a game of luck like Backgammon and ESPECIALLY in a game of much luck like Hypergammon, is something no one can achieve! Only if his opponents were random-movers. But i guess they were human species with a kind of intelligence.

Assume that someone is very skillful at Hypergammon. That would give him let's say a 58% advantage over his opponents to win a game since at Hypergammon even a huge skill difference is rejected by the huge luck factor in this game.
Then in order to win both 20 games the probability of that is 0,0019% or 1 to 54000.

Also if you see some of his games you can obviously see stupid play from his opponents.....

Alsi i wonder why he plays with an ix almost every time.....?

i would take the double hit, leaving only 1 single, and your opponents board empty so you would have no problem getting back on the board

redsales: *nod* thats why i thought it to be a very good move :) its often very nice to know your opponent in bg

btw in the messages i the game redsales worked even more towards this point by stating 'one is going down hard in this game' (or something like that :)) .. i had to agree (with a smile :)) and next turn i felt like i had to drop the double :)

redsales: "i knew you were nervous about experimenting!"

It can sometimes be said that asking questions about a game in progress gives an advantage to the one asking. Not this time!

Quick definitions: didactic - adjective: instructive (especially excessively)
Wot me?

"gaining blocks" - poor choice of words given that there's the standard "making points".

1) I'd do the double-tap. If hit there's every chance of making a nice anchor with the blots on 5 and 4 so it wouldn't be a total disaster. GnuBg says .. double-tap for best move. It says to hit one of the blots with the next 3 choices and making the 2-point is only 5th and a blunder! (-.100) The hitting priority doesn't surprise me because tapping a naughty blot sharply on the nose is the thing to do at the beginning but I'm surprised that making the point is considered blunderful. I guess another part of that is because the blocking effect has been lost given that the point is behind the escaping backrunners. A kind of bolting the stable door thing.

2) Striking opening examples where non-cube (or rather non-gammon) is different from cube. Hmmm. I can't think of anything striking offhand. I tend to play gammonish anyway and have to remind myself not to.

playBunny: Direction button. Got it. Works now. THANK YOU. (And Thank God too- because I'm not sure I would have been able to go on with this otherwise great book!)

OK， new question. In this game:

1) would you play the double hit on the 6-4 roll?
i didn't, because without the cube, i didn't feel that taking the risk of "squandering" a 10 roll for no chance of the increased reward of a gammon was worth it...leading to the second question...

2. could this be one of the situations where you'd play differently based on a cube or not? If it's not, what's the most striking opening example you can think of?

Also, playbunny, i don't understand the terminology of "gaining blocks", hoping for something didactic here!

http://brainking.com/cn/ShowGame?g=1406288

Hrqls: wellllll...i knew you were nervous about experimenting! I really didn't want to double, that game was fun! But..i like points too..

playBunny: "I wouldn't have doubled in that position - unless I had hopes of frightening you off. ;-)."-Playbunny

Couldn't agree more!

Read that again for anyone who dares compare BG to chess!!

DragonKing: Isn't it confusing! You get the same with text printouts in certain newsgroups but worse because a text board has an added strangeness.

There's no official direction of play so when I was first taught to play on a real board we used to play as different colours and have the home tables on different sides, just to get used to playing it any which way. Since playing on the Net I've become very fond of playing it just the way it is here (and at most other sites). Anyway ..

.. there's a button on the right end of the GnuBg toolbar called Direction. Give it a poke and see if you like what it does. ;-)

I have a rather amateurish question about one of the books by Bill Robertie. The book is "Backgammon For Winners". The book appears to have all the information I want to learn as a new player-BUT- what is the problem with his diagrams? What point of view are they from? Because they seem to be mirror images of the board when I play with GNU. I thought at first it was just a top to bottom thing, but when I turned the book upside down- I realized that right and left are reversed from his diagrams to the board I'm using?? "What's up with that?" I'm finding the book very hard to use now. (I also have, "Starting Out in Backgammon" by Lamford and his diagrams are just like my board.)

Pedro Martínez: Correct, on closer inspection one of the games is clearly rigged. That and the Asterix-like names I'd say the prosecution can rest.

Shall we petition for removal, and possible execution?

grenv: Look at those two games with Patafix...I find it hard to believe that someone who wants to win would not hit a blot in the opponent's base - especially in hyper BG.

Pedro Martínez: I'd agree, those nic's are obvious and the play sure isn't steller,

Pedro Martínez: Hard to say, the few games that aren't private look legitimate, the others at least took a few turns.

By the way can we please get rid of private games, they are not needed.

http://brainking.com/cz/Profile?u=11403&eg=66&dy=2006&p=1

grenv & playBunny: hmm might be true indeed .. the game wasnt that far advanced yet .. and i played for 4 (or 2*gammon) in the other match with him as well (and got 4-0 behind ;))

i guess i was scared .. i wonder if he doubled because of that ... redsales .. did you ? ;)

grenv: I just wanted to give a flavour. I added some stuff about gammons and then took it out again. I left all that to the experts at the other end of that link. (There are more articles about equity in the Terminology list at the foot of the article linked to.)

It seems you can be in a better chance to win a gammon than your opponent, but a worse chance to win in general?

playBunny: Ah, but gammons and backgammons are counted, so you may have a 50% chance of winning but a positive equity if your chance of gammoning is better than your opponent. right?

Czuch: Yep. Positive mean you'll win more than you lose, negative means your opponent will win more than they lose. Equity of 0 means the position is 50-50.

Equity

playBunny: I think I am confusing myself!
But, the higher the equity number, the more likely a win?

Czuch: I don't understand. What's the difference?

Now for those roll outs... Does the equity mean that its the best play at that time compared to other possible plays, or does it show what is most likely to afford a win?

Czuch: ..is somebody grumpy today?

I'm teasing but there is an edge of grumpiness. I'm really knackered and I'm probably going to get into trouble next week for something I didn't attend and I'm waiting impatiently for some important news and .. Lol. You sussed me!

Czuch Chuckers: Is there really only one best play for every given situation?

Yes, but. With perfect knowledge there is almost always going to be abest play, the only exceptions being when there's a tie. But we don't have perfect knowledge and nor do the computers .. yet.

Maybe what is a good play against another computer wont be a good play against an amateur?

Let's change it round a bit .. a good play against an amateur might not be a good play against a computer

Not only against an amateur but even against the different robots (though that level of subtlety in way beyond me). The "perfect" moves as reported by any of these computers is only perfect against itself. However that doesn't mean that they are wrong, it means that in certain situations they'll be slightly less than optimal. There's a huge amount of agreement between the top robots.

Against amateurs you'll find that there are definitely situations where you can make what would be a bad play against a computer or top player. For instance I'll leave a vulnerable blot in certain situations. The computer would jump on it with glee but it's safe when played against some opponents because they are too scared to do the hit. And that blot then gives me more options to hit them, or has them making poor choices in order to avoid the danger that it poses. Generally, with a player who puts too much emphasis on safety, you can get away with, and should try, things that would get you a slap on the wrist from the computer.

Putting it the way that you did, where the good play against the computer is bad against the amateur, is less frequent, I'd say. The good moves will always be good moves, even if not the best against that particular player in that game.

playBunny: ..is somebody grumpy today?

Czuch Chuckers: it gave incorrect info

Interestingly Backgammon, written by Paul Magriel in the 70s, is considered to be the "Bible" of Backgammon. It's a book that many a champion has devoured and is highly recommended left, right and centre. This is despite that fact that it contains a lot of errors as proved by today's computer rollouts.

playBunny: Curious.... on these roll outs, what happens at the nmid game, ie how is it determined which move is best? There is obviously no gauranteed win for every combo of rolls? Maybe what is a god play against another computer wont be a good play against an amateur? Is there really only one best play for every given situation?

Czuch: BTW... last time I looked at one of your charts it gave incorrect info.

Yup, best not to look at any charts ever again. No data is always preferable to good data with an error or two.

Czuch Chuckers: Is that your top three?

3-1, 4-2, 6-1 is the order. Home point, home point, bar point. A blocked bar point is handy but it will never prevent someone coming in off the bar.

BTW... last time I looked at one of your charts it gave incorrect info.

3 1?
6 5?
4 2?

Czuch: but you get to learn so much more.

Guess again..

playBunny: Thats no fun!
My guess.... 6 1

Czuch: It's time to learn how to read the numbers, Czuch. Go have a look at the opening move rollouts. ;-)

Hrqls: You had a slightly better home, he might have danced, you had good options to continue the attack or go defensive and make the barpoint anchor. The four backrunners of yours gave redsales the advantage but it wasn't conclusive by any means. Plenty of scope for you to turn the game. I wouldn't have doubled in that position - unless I had hopes of frightening you off. ;-).

Hrqls: Definitely a take in my opinion as well. You had an inferior position, but not that inferior. Control of the cube is important.

What opening roll has the highest likelyhood for a win?

playBunny: really ????? no way!
hmm maybe i was too chicken :)

i would have continued if he had not doubled .. but i didnt dare to play it for 2 points (or gammoned 4) :)

Hrqls: Lol. You played that one well until that last move - it was a take!

playBunny: wow i would never expected .. you are right about the vulnerable piece on 11 though :)

i am on a roll for luck in that game .. i tell myself i should play more safe now .. but i cant help it with this start :)

Hrqls: 12/14  1/2 would have been very bad because there were two men facing you: a direct 6 and the highest indirect shot, 7. Better is to fight for the 5-point with 6/5* (20/19*) and bring down the support with the 2 - 13/11 (14/12). But best there is the double-tap/double-slot that you did.

grenv: even when leaving 2 singles in my home ? *shiver* :)

Hrqls: oops, i misread it, i thought it was 5-2 from the 8 point. In this case your move is probably best.

playBunny & grenv: lol! i tried it out against redsale .. i would have done 12-14,1-2 normally .. but i wanted to try it out because of this conversation and it even happened in a game at the same time :)

he sent me to the bar with 1 piece .. the other is still there .. lets see what this will bring me :)

Hrqls: That first example where you drop two blots onto your 2-point and ace point.. that's a big no-no. Blots in your home table should be working for a living - that means either preparing to make high points or hitting twice and going deep (eg 4-1:  6/5*/1*). There are times when you'd hit with two blots, such as your opponent opening with a (doubtful but not bad) 4-1:  24/20  24/21. If you then roll a 2-1 you'd hit them both. You gain a tempo plus the chance to make one or both of those valuable points on your next go. [LOL. You were busy posting while I was writing this. The redsales games is that exactly!] Gaining blocks on 2 and 1 is very inferior.

In your own game example I would have done that hit. I frequently do a double-tap with a single man from the 6 or 8 points when given the opportunity.

grenv: ok .. like in this game

grenv: it seemed to work out ... i am still there :) (although a double 6 from his side would have been best for me ;))

how could i make my 4 point when rolling 2+3 ?