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Old 07-13-2021, 01:39 PM   #26
_Z_
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Re: Random Observations xg vs galaxy - somewhat new player

You wouldn't do the calculation over the board to figure out winning percentage in the first position you posted, you should just memorize the percentages for 2, 3, 4, and 5 roll positions. Then you can use those numbers in simpler calculations or to help make an informed guess.

For instance, the second position you posted, you can do a little calculation and be 100% sure you have a take in a money game. My reasoning over the board would go like this:

White's clearly better than a 3 roll position, so he's more than 21%. How much better? If Black rolls 2 consecutive 2s, it turns a very likely loss into a very likely win. 2 consecutive 2s happens around .3 * .3 so like 9%. A lot of that 9% should get added to 21% probably pushing me above 25% right there. And there's other stuff going on, like double 1s and doubles 2s don't save a roll for Black, so surely this well above 25% and an easy take.
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Old 07-13-2021, 01:42 PM   #27
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Re: Random Observations xg vs galaxy - somewhat new player

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Originally Posted by MarkD View Post
Game 3 of a 3 game match and I'm winning 2-1. Opponent starts and rolls 6-4 -> 24/14. I roll 5-4 -> 13/9 13/8. He doubles. I take. I make a -0.217 error by taking and I'm supposed to pass?

I don't understand this as I thought these would just be automatic takes. I guess it says I'm a 55/45 dog in this situation and if I pass I'm 50/50 again... This is crazy.
Yes, that's the correct reasoning. Similar reasoning applies whenever your opponent needs an even number of points post-crawford. If he needs an odd number of points, you should pretty much take everything, as losing 1 point is almost as bad as losing 2. If that's not obvious, think carefully about the 1-away 3-away score post-crawford.
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Old 07-13-2021, 01:55 PM   #28
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Re: Random Observations xg vs galaxy - somewhat new player

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Yes, that's the correct reasoning. Similar reasoning applies whenever your opponent needs an even number of points post-crawford. If he needs an odd number of points, you should pretty much take everything, as losing 1 point is almost as bad as losing 2. If that's not obvious, think carefully about the 1-away 3-away score post-crawford.
It's obvious, but what is not obvious is that I would be a big dog after these two rolls. It's not even obvious to me that I am a dog after these two rolls. I guess he is ahead on the race and has escaped a checker and I failed to hit, but I also have a lot of builders.

Now that it's happened I'm guessing there are a lot of sequences like this that I need to be aware of and drop more often - I've been assuming these were automatic takes.
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Old 07-13-2021, 01:58 PM   #29
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Re: Random Observations xg vs galaxy - somewhat new player

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Originally Posted by _Z_ View Post
You wouldn't do the calculation over the board to figure out winning percentage in the first position you posted, you should just memorize the percentages for 2, 3, 4, and 5 roll positions. Then you can use those numbers in simpler calculations or to help make an informed guess.

For instance, the second position you posted, you can do a little calculation and be 100% sure you have a take in a money game. My reasoning over the board would go like this:

White's clearly better than a 3 roll position, so he's more than 21%. How much better? If Black rolls 2 consecutive 2s, it turns a very likely loss into a very likely win. 2 consecutive 2s happens around .3 * .3 so like 9%. A lot of that 9% should get added to 21% probably pushing me above 25% right there. And there's other stuff going on, like double 1s and doubles 2s don't save a roll for Black, so surely this well above 25% and an easy take.
Awesome, this is what I was looking for to help me understand this chapter better, but I honestly have bigger leaks to fix.

All of these are from the same game:








I start thinking that I am making progress than I play a game like this.
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Old 07-13-2021, 01:59 PM   #30
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Re: Random Observations xg vs galaxy - somewhat new player

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Originally Posted by MarkD View Post
It's obvious, but what is not obvious is that I would be a big dog after these two rolls. It's not even obvious to me that I am a dog after these two rolls. I guess he is ahead on the race and has escaped a checker and I failed to hit, but I also have a lot of builders.

Now that it's happened I'm guessing there are a lot of sequences like this that I need to be aware of and drop more often - I've been assuming these were automatic takes.


You're losing mostly because he's on roll.
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Old 07-13-2021, 02:07 PM   #31
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Re: Random Observations xg vs galaxy - somewhat new player

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I start thinking that I am making progress than I play a game like this.
Join the club.
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Old 07-13-2021, 03:42 PM   #32
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Re: Random Observations xg vs galaxy - somewhat new player

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Join the club.
I have the feeling you aren't making multiple 0.1 and 0.2 errors in a single game.
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Old 07-13-2021, 05:49 PM   #33
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Re: Random Observations xg vs galaxy - somewhat new player



Latest problem position I had. Actually had quite a few in this game, but this one I struggled with a lot.

So, it's a match to 3 and I've doubled.

I immediately look at 9/8* 8/4*, and this was my thought process over the board

Benefits:
  1. Puts two checkers on the bar
  2. Increases gammon chances
  3. Slots a point in my home board

Cons:
  1. Leaves 13 direct return shots
  2. Of those 3 shots (44, 45) send back two men and I probably lose
  3. His timing is good if he gets in and I probably lose a lot of games

Alternatives:
  • 6/1 - retains my flexibility and gives me a few more rolls to come in safely. He's given up the 4 point and I can make that safely with 52, 32, 22. Not a lot, but something.
  • 7/3 7/6 - Ugg. Gives up a landing spot for my checkers on the 9 and stacks up the 6 even more.

SO... I choose 6/1 after a significant amount of thought.

What to do?
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Old 07-13-2021, 06:09 PM   #34
MarkD
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Re: Random Observations xg vs galaxy - somewhat new player

Ok, so I'm thinking it through a bit more:

- I only really dislike the sequence where he hits me and I fail to get in which is ~ 1/3*1/2 = 1/6. Do I lose all of these? no, but I am in big trouble with my blot on the 9 and his strong home board.
- If he fails to get in (2/3) I'll cover with any 2,3, 5 which I think is 27 rolls, or 3/4 which is 3/6 games
- 2/6 games I probably have a ton of equity after the double hit and he fails to come in.

So, I win 5/6 and lose 1/6. I know this isn't correct but I'm trying to come up with a method I could use over he board to estimate the situation.

Now, I need to compare that to 6/1. Which I'm not sure what to do... but the double hit is looking better now.
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Old 07-20-2021, 12:55 PM   #35
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Re: Random Observations xg vs galaxy - somewhat new player

Quote:
Originally Posted by MarkD View Post
Game 3 of a 3 game match and I'm winning 2-1. Opponent starts and rolls 6-4 -> 24/14. I roll 5-4 -> 13/9 13/8. He doubles. I take. I make a -0.217 error by taking and I'm supposed to pass?

I don't understand this as I thought these would just be automatic takes. I guess it says I'm a 55/45 dog in this situation and if I pass I'm 50/50 again... This is crazy.
Anyone playing a long time would pass in a second. Think about it - you can play this game for the match and win the match 45% of the time. Or you can pass, start a new game for the match which you win 50%.

Stick with it. These things come easier in time. It's a difficult game and don't expect everything to come together right away.
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