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Old 02-20-2017, 02:59 PM   #1
Don Kament
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Second best move is already a blunder.... Why?!

Hi folks,

i like to get better at backgammon! Part of my training strategy is to look for errors i made, where the second best move is already a blunder. There are some positions where i´m able to figure why it is a blunder, but most of the time i´m pretty clueless. That´s what i like to change. So please share your thoughts about the positions i´m going to post.

Thanks in advance!
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Old 02-20-2017, 03:09 PM   #2
Don Kament
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Re: Second best move is already a blunder.... Why?!

Position 1.

White - Pips 121. Match Score 0/7

Black - Pips 38. Match Score 0/7
Black to Play 1-1
Created with www.BGdiagram.com

Hero blundered:
Spoiler:
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Old 02-21-2017, 06:45 AM   #3
Don Kament
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Re: Second best move is already a blunder.... Why?!

Hi again,

i think i should have included the analysis of GnuBg and what i thought about the position, so here it is.

Spoiler:
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Old 02-21-2017, 10:22 AM   #4
Robertie
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Re: Second best move is already a blunder.... Why?!

You've got several different goals when bearing off against an ace-point game. Sometimes they conflict, and then you may have a tricky play.

Here, for instance, one goal is to be even-ended. That's what your play accomplished.

A second goal, which is usually even more important, is to avoid what I like to call the pseudo-gap. In this position, a pseudo-gap appears when you have spares on the 4-point and 2-point, but no spares on the 3-point. You don't have a real gap (an open point) but your spares themselves are gapped.

You can see the problem with a pseudo-gap when you actually count the shots that leave a blot next turn. With your actual play, you leave a shot with 6-3, 5-3, 4-3, and 3-2, a total of 8 blotting numbers. After the better 5/3(2), you've eliminated any pseudo-gap possibilities and now you leave a shot with only 6-5, 6-4, and 5-4. (6 numbers)

But we're not done quite yet. If you make your play and then roll 6-5, 6-4, 5-4, 6-2, 5-2, or 4-2 (12 other numbers) you'll either take two off or take one off and play 4/2 with the other. In either case you'll leave yourself with two checkers on your 4-point and two checkers on your 3-point. Now rolls of 6-3, 5-3, and 4-3 will leave two blots! This double-blot variation won't arrive after the better play.

Hope this helps.
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Old 02-21-2017, 12:58 PM   #5
Don Kament
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Re: Second best move is already a blunder.... Why?!

Hi,

I´m feeling a bit sheepish about failing at counting the numbers which leave a shot... If i would have done that correct, i think i would have moved 5/3(2).... So i guess i need some practice at counting numbers which leave a shot. Thanks a lot for your hint about the pseudo-gap! I will definitely watch out for it the next time in bear off!!!

Before i post the next position, i promise i will put in some more thought. There is another bear off position, where i chose the wrong move. Let´s see if it is some kind of pseudo-gap problem.
Hopefully we can get something going here. If anyone likes to post a position that fits the thread (i would suggest only if the previous question has been solved) - feel free to do it!

Kind Regards
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Old 02-22-2017, 09:38 AM   #6
Don Kament
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Re: Second best move is already a blunder.... Why?!

Hi folks, here is the next one. I have thousands of them

Position 2.

White - Pips 160. Match Score 0/5

Black - Pips 157. Match Score 1/5
Black to Play 3-1
Created with www.BGdiagram.com

Heros move and GnuBg Analysis:
Spoiler:


Whys and best guess:
Spoiler:
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Old 02-23-2017, 11:21 AM   #7
Robertie
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Re: Second best move is already a blunder.... Why?!

Bar/24 13/10 gives you a solid and pretty safe way to pursue your main goal, building a prime against your opponent's three back checkers. If you leave your blot on your 8-point as a builder (which you should), you're subject to 6 shots. Playing 13/10 just adds two more shots, which isn't a big deal. Since your back checkers are anchored, he rates to miss his shots, after which you'll have plenty of rolls to entend your prime, either from the front or the back.

When you split with Bar/24/21, everything changes. Your opponent now has all 4s and 2s plus 6-3 and 3-3 to hit your checker on his 4-point. Many of those rolls allow him to hit and split his back checkers, giing him a new direct shot at the blot on your 8-point.

If he hits and you roll poorly from the bar, your opponent might make a stronger board, or keep moving his back men and get an anchor, squashing your chances of priming him. You were probably thinking that because he didn't have a lot of builders, you weren't in much danger. But what's actually going on is that you've given him some new possibilities.

(1) While you're entering from the bar, he may be moving his back men and getting an anchor.

(2) If you start dancing, he may get a blitz going. Remember, he already has a stronger board, and since he's already made two low points a blitz is his natural game plan.

A good exercise for positions where you have questions is to set the position up on a real board and play a few games, some starting from Bar/24 13/10 and others starting from Bar/21. Watch what happens, and you'll start to see why 13/10 is a better play.
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Old 02-23-2017, 03:26 PM   #8
Don Kament
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Re: Second best move is already a blunder.... Why?!

Thank you for your insights sir! I really appreciate that very much!

So i was basically overestimating the risk of getting hit after playing bar/24 13/10 and underestimating the risk of getting hit after playing bar/21. That´s what i´am doing all the time - overetimate / underestimate risk and reward in backgammon.... I even supported the game plan of my opponent, since gnu has to hit right? With bar/21 there are a lot more shots than after bar/24 13/10.

If it is ok, i really like to keep this going. Hopefully more people join the discussion. (I don´t have to mention that it´s awsome that a two time world champion already joined the thread )
I´m going to post positions where i blundered and the second best move is already a blunder, since i think there has to be some concept behind i´m not getting right.
I will always spoiler the analysis of gnu and my thoughts so that everyone could make a guess without any influence.

I won´t just post them right after play. I will try to find out where my thinking was flawed and by the way - I really played that position a few times with gnu.

Like i said, i hope that people join the discussion and it is going to be an epic thread.

Finally i like to mention that i´m not a native speaker. If i make any errors that make you scream "Ahhhhhhhhhhhhhh, i´m gonna kill this guy if have to read another word..." please let me know before

Have a good day / night!
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Old 02-24-2017, 10:58 AM   #9
Robertie
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Re: Second best move is already a blunder.... Why?!

Your written English is already a lot better than many Americans. Keep up the good work!
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Old 02-25-2017, 05:02 PM   #10
Don Kament
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Re: Second best move is already a blunder.... Why?!

Thanks again!

Here we go. I recently switched to XG and this position came up. The result of the analysis was very surprising to me and some kind of eye opener, hopefully for someone else too!

Position 3:

White - Pips 145. Match Score 2/7

Black - Pips 85. Match Score 0/7
Black to Play 2-3
Created with www.BGdiagram.com

Heros move and XGRoller++ analysis:

Spoiler:


Whys and best guess:
Spoiler:

Last edited by Don Kament; 02-25-2017 at 05:09 PM. Reason: spelling, grammer
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Old 02-25-2017, 06:15 PM   #11
Karol Szczerek
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Re: Second best move is already a blunder.... Why?!

Basically, if your opponent doesn't have a really strong prime, and you have 5-4-pt. board with spares, you just always loose hit the second guy inside your home board to try for a gammon (if your gammons count at the current match score, of course).

If you don't hit and he covers that's a real disaster, cutting off a majority of your gammons. If you loose hit and he hits (most often with only one guy, while the other will stay on the bar), that's a much lesser evil. You can still enter fast and continue the attack.

What really surprised me was, that even when i get hit with 21, i´m still a 75% favorite to win the game.

You have a mountain of spares in the zone and you face only 2pt. board from a bar. Majority of your rolls enter and hit the guy on the bar or loose hit inside your home board, reopening the blitz route. Until he anchors, you're on a fast track to a closeout and gammon.
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Old 02-27-2017, 03:41 AM   #12
Don Kament
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Re: Second best move is already a blunder.... Why?!

Quote:
Originally Posted by Karol Szczerek View Post
Basically, if your opponent doesn't have a really strong prime, and you have 5-4-pt. board with spares, you just always loose hit the second guy inside your home board to try for a gammon (if your gammons count at the current match score, of course).

If you don't hit and he covers that's a real disaster, cutting off a majority of your gammons. If you loose hit and he hits (most often with only one guy, while the other will stay on the bar), that's a much lesser evil. You can still enter fast and continue the attack.

What really surprised me was, that even when i get hit with 21, i´m still a 75% favorite to win the game.

You have a mountain of spares in the zone and you face only 2pt. board from a bar. Majority of your rolls enter and hit the guy on the bar or loose hit inside your home board, reopening the blitz route. Until he anchors, you're on a fast track to a closeout and gammon.
Thanks for your comment. Aside from not knowing that anchoring is such a "disaster" i recently realised that i have some predefined goal in my mind before the roll, which tends to some kind of clouds my thoughts. I tend to make plays that follow that predifined idea even if there are new opportunities after the roll. I think i have to take more time before i make my move and thinking about the goals more neutral... Anyway, i was surprised by the numbers so i think there is some homework to do!

Thanks for your insights - new position is coming soon

Last edited by Don Kament; 02-27-2017 at 03:42 AM. Reason: spelling
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Old 02-27-2017, 08:00 AM   #13
cboevey
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Re: Second best move is already a blunder.... Why?!

The theme of the position is that you do not want him to anchor up under any circumstances. Note that 10 percentage point difference in Gammons between the correct play of hitting and anything else. Even if he does come in hitting you - so what? He's got another guy on the bar, and a loose blot in indirect range. He doesn't have a scary board, so you're much more likely to come in and run around before he gets two guys in, over your prime and contains one of your guys.
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Old 02-27-2017, 11:18 AM   #14
Robertie
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Re: Second best move is already a blunder.... Why?!

Good analysis from Karol and cb.
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Old 03-02-2017, 05:30 AM   #15
Don Kament
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Re: Second best move is already a blunder.... Why?!

Hi folks,

i bet i´m the only one here that make this kind of errors....

Position 4:

White - Pips 143. Match Score 2/5

Black - Pips 143. Match Score 2/5
Black to Play 1-1
Created with www.BGdiagram.com

Heros move and XGRoller++ analysis:
Spoiler:


Whys and best guess:
Spoiler:
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Old 03-02-2017, 10:57 AM   #16
cboevey
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Re: Second best move is already a blunder.... Why?!

Quote:
1) Why is making a blocking point (the bar) in this case such a bad idea?
Ok, I'll have a go. I tend to get some of these wrong some of the time so buyer beware. In the initial position, one of the priorities is to get that back guy out of there. You've been given a golden opportunity to achieve two goals, make another point and move the back guy so that a 6 in the future allows you to jump his prime with minimal risk of him hitting you off the two point in the near future. Also, making the 654 points is a very strong asset to have, so the correct move achieves two pretty good things as opposed to just one by making the blocking point (I read that concept in a Robertie book).

Note in your variations where the back checker can escape with a 6 or not, if it can't, making the bar point has the bonus of making the blot on the 10 safe.

Quote:
2) What are the things to consider, that make moving in front of a prime mandatory?
Stepping up is good when he has no builders in direct range i.e. opponent would have to break his prime to hit the blot directly. Is the back of his prime slotted or not? Can you escape directly with a 6 or 6 and 5 are considerations. How is the other side of the board looking? Are you ahead in the race? If you escape, do you have a reasonable chance of winning? Sometimes it is best to hang back especially if the prime is an outside prime, such that he can't play behind you. Are you priming him i.e. is it prime vs. prime? There is actually a lot more to consider. It's going to take some practice to develop a feel as to how to weigh the considerations. But keep the positions coming!
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Old 03-03-2017, 03:32 AM   #17
Don Kament
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Re: Second best move is already a blunder.... Why?!

Quote:
Originally Posted by cboevey View Post
Also, making the 654 points is a very strong asset to have, so the correct move achieves two pretty good things as opposed to just one by making the blocking point (I read that concept in a Robertie book).
Haha, I even read that concept too... Thanks for reminding me. There are so many things to consider when those positions arise in a match, that it´s easyily overwhelming me. Anyway, at least i´am thinking about the errors i make and hopefully i get rid of most.

So don´t be afraid, there are more positions to come . I think it´s possible to post at least one, maybe two positions a week.

Thanks for your answer, i really appreciate that!
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Old 03-09-2017, 09:46 AM   #18
Don Kament
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Re: Second best move is already a blunder.... Why?!

Position 5:

Second best move is a -0,1335 blunder!

White - Pips 169. Match Score 0/7

Black - Pips 152. Match Score 0/7
Black to Play 2-2
Created with www.BGdiagram.com

Heros move:
Spoiler:


Analysis:
Spoiler:


What do you think?

Kind Regards!
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Old 03-09-2017, 10:09 AM   #19
cboevey
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Re: Second best move is already a blunder.... Why?!

A lot of my blunders are playing doubles. The correct play creates 2 assets, the 4 point and 11 point, as opposed to 1 with any other play. You're not so worried about the blot because he doesn't have as strong a board as you do. Moving to the 13 and leaving it there creates a big stack that will be difficult to unload. What are you going to play for next roll? A lot of your rolls that include a 6 are quite bad.
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Old 03-09-2017, 12:38 PM   #20
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Re: Second best move is already a blunder.... Why?!

After making the 4, you can safety the checker in your opponent's outfield or you can make a valuable point. Both are good things, but often making the point takes precedence in the opening, unless maybe if you don't have any other checkers on your opponents side of the board. But even then, locking up the concrete asset could be better.

Here, the safetying play is especially problematic because it messes up the distribution with 6 guys on the 13 point and a stiff position. Compare to the other play where things are a lot more flexible.
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Old 03-09-2017, 01:08 PM   #21
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Re: Second best move is already a blunder.... Why?!

Come to think of it, if you are going to play 17/13 with the first two 2s, you might be better off making the 11 than the 4 with the next two. The 4 is a better point than the 11, but the 11 is still quite good with the White blot on your 5 point and the distribution is much better.
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Old 03-09-2017, 02:33 PM   #22
Robertie
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Re: Second best move is already a blunder.... Why?!

Back in high school, I had a coach for the chess club who constantly repeated the same advice to his motley crew: "Sit on your hands!"

His point was -- don't make a move until you've looked around the board and checked out some alternatives. Otherwise, you'll jump to make the first good move you see and won't look around for a better play.

The same advice works in backgammon. It's easy to see that 17/13 picks up a blot, and 6/4(2) makes an inner point, so if you're excited and rushing the play, you'll just make that move and pick up the dice, not noticing that there are a couple of other plays to consider.

The merit of 4(2) 11(2) is that it makes two very good points at a very moderate risk. The 4-point is good because it's an inner point, but it's even better because the 3-point/6-point combination isn't very strong until you fill in either the 4-point or the 5-point, after which you have a really good position. The 11-point is good partly because it puts permanent pressure on your 5-point, and partly because it unstacks. You've got a big ugly stack on your midpoint, and playing 17/13 just makes it worse.

Look at it this way: a blot can be a weakness, and a big stack can be a weakness. But a blot only hurts you if your opponent hits it (which he's not favored to do), while a stack hurts you no matter what your opponent rolls!
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Old 03-11-2017, 05:22 AM   #23
Don Kament
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Re: Second best move is already a blunder.... Why?!

Quote:
Originally Posted by Robertie View Post
Back in high school, I had a coach for the chess club who constantly repeated the same advice to his motley crew: "Sit on your hands!"

His point was -- don't make a move until you've looked around the board and checked out some alternatives. Otherwise, you'll jump to make the first good move you see and won't look around for a better play.

The same advice works in backgammon. It's easy to see that 17/13 picks up a blot, and 6/4(2) makes an inner point, so if you're excited and rushing the play, you'll just make that move and pick up the dice, not noticing that there are a couple of other plays to consider.

The merit of 4(2) 11(2) is that it makes two very good points at a very moderate risk. The 4-point is good because it's an inner point, but it's even better because the 3-point/6-point combination isn't very strong until you fill in either the 4-point or the 5-point, after which you have a really good position. The 11-point is good partly because it puts permanent pressure on your 5-point, and partly because it unstacks. You've got a big ugly stack on your midpoint, and playing 17/13 just makes it worse.

Look at it this way: a blot can be a weakness, and a big stack can be a weakness. But a blot only hurts you if your opponent hits it (which he's not favored to do), while a stack hurts you no matter what your opponent rolls!
I recently started to categorize my blunders and guess what - there is a category named "DidNotRecognizeThatPlay". Currently there are 7 positions/blunders in that category followed by "ToAggressive" and "ToPassive" (also 7 positions) category. So, i think i have to calm down myself and give it another thought when i think i found the best play.

What i could also have done, to find out why the save play was wrong, was to play that position out a few times, which Mr. Robertie already pointed out

Thanks again guys for your insights! Please keep it up. I won´t stop this until my PR drops under 5.



It´s not an easy road

Have a nice weekend folks!
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Old 03-13-2017, 07:54 PM   #24
ClassicalGuitar23
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Re: Second best move is already a blunder.... Why?!

Getting to under 5 is a LOT harder than it appears
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Old 03-14-2017, 05:37 AM   #25
Don Kament
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Re: Second best move is already a blunder.... Why?!

Quote:
Originally Posted by ClassicalGuitar23 View Post
Getting to under 5 is a LOT harder than it appears
No disrespect. I´am totally aware of it... Let´s see what i´am able to achieve.

Last edited by Don Kament; 03-14-2017 at 05:41 AM. Reason: Grammar
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