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Play Against Probilities? Play Against Probilities?

02-13-2011 , 08:30 PM
How do y'all think? (It's a real wurd whur ah come frum.)

Here's how I think in many instances:

"If I do 'this' (which appears to be the best move), it is very unlikely that he will roll 'that.' However, IF he does indeed happen to roll 'that', I'll be in a horrible position, so I'll play it another way."

Is this what y'all do, or do you stick stubbornly with the odds?

Last edited by geneftw; 02-13-2011 at 08:33 PM. Reason: Went back to mispell another word. :)
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02-13-2011 , 11:17 PM
Quote:
Originally Posted by geneftw
"If I do 'this' (which appears to be the best move), it is very unlikely that he will roll 'that.' However, IF he does indeed happen to roll 'that', I'll be in a horrible position, so I'll play it another way."
Well your scenario above all boils down to how much risk you can afford. If your opponent owns the cube and you're ahead and are just trying to finish the game on top, then you'll probably play conservatively. If you are behind in match play and need to get something going and make something happen, you might make the riskier play. But the odds will help you decide how much risk you'll have to take to make a certain move, but they won't necessarily determine whether or not you should take that risk (unless they are extreme in some way). We shouldn't be afraid of our opponent's jokers, because they are long shots, and the odds tell us that we'll come out ahead against the jokers in the long run, right? So in a cash game, making plays that give you good odds to make points, hit checkers, and build primes are always going to be good plays, I would imagine. If your opponent gets a great roll to stop you, there's nothing you can do about it. But if you're in match play, then the score will influence your decisions somewhat.
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02-13-2011 , 11:58 PM
That makes sense, and I guess I knew that intuitively...It's just not something I've ever tried to put in words.--And it makes me doubt, to some extent, the validity of all that math stuff. Sure, the odds of this roll are X%, but it's left up to the player-not the math-to make the final decision.
"If he does roll that 53 after I play this way, how bad will it hurt me? Hmmm....If he rolls that 53, my odds of recovering are slim...I might even lose a gamon."
In this case, I say those odds can take a flyin' leap. I'll make another play.
Play Against Probilities? Quote
02-14-2011 , 12:17 AM
Quote:
Originally Posted by geneftw
How do y'all think? (It's a real wurd whur ah come frum.)

Here's how I think in many instances:

"If I do 'this' (which appears to be the best move), it is very unlikely that he will roll 'that.' However, IF he does indeed happen to roll 'that', I'll be in a horrible position, so I'll play it another way."

Is this what y'all do, or do you stick stubbornly with the odds?
I stick stubbornly to the odds. All this non-math stuff is too hard for me.
Play Against Probilities? Quote
02-14-2011 , 12:28 AM
Quote:
Originally Posted by geneftw
Here's how I think in many instances:

"If I do 'this' (which appears to be the best move), it is very unlikely that he will roll 'that.' However, IF he does indeed happen to roll 'that', I'll be in a horrible position, so I'll play it another way."
Not saying you should never look out for jokers, but I would say if you're "often" worried about joker rolls and going out of your way to avoid them, then that's probably a mistake.

Money game, what's your play?

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02-14-2011 , 12:31 AM
@Robertie:
That's why I'll never be a pro. I can't see sticking to the odds if I'm sure to lose when those odds are violated. If I play a less favorable move, I'm at least still in the game rather than being killed for (almost) certain by a "surprise" roll.

Last edited by geneftw; 02-14-2011 at 12:45 AM.
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02-14-2011 , 12:37 AM
"...What's your play?"

I'll play 13 to 5. I've just about got the game won, and I'd rather win a "mere" single game than to lose the won game on the hopes of winning the extra point. If I put my checker in that 4 hole, Black "probably" won't hit it........But if he does, I've given away a won game.

BTW: I do not worry about jokers so often that I can't build a good position. I consider the position you posted to be a perfect example (maybe a bit extreme) of when I say, "To Heck with those dang odds!!"

Last edited by geneftw; 02-14-2011 at 12:43 AM.
Play Against Probilities? Quote
02-14-2011 , 12:41 AM
Quote:
Originally Posted by geneftw
"...What's your play?"

I'll play 13 to 5. I've just about got the game won, and I'd rather win a "mere" single game than to lose the won game on the hopes of winning the extra point. If I put my checker in that 4 hole, Black "probably" won't hit it........But if he does, I've given away a won game.
Yeah, slotting the 4-point is lunacy here, but there still is a better play than 13/5.
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02-14-2011 , 12:53 AM
13/8, 13/10 would stink, too (Or any move that puts a checker on the 8.) If he rolls 44, I'm dead. Once again, he probably won't roll 44, but IF.....

I'll admit that sometimes I would play the 13/8, 13/10....When I'm in a gamey sort of mood.

EDIT:
I've never done roll outs on my bot, don't know how long it would take, but I'd be willing to bet 2 bunches of bananas and 100 termites that 13/5 would come out ahead of putting a checker on the 8.

Last edited by geneftw; 02-14-2011 at 01:03 AM.
Play Against Probilities? Quote
02-14-2011 , 01:06 AM
Quote:
Originally Posted by geneftw
EDIT:
I've never done roll outs on my bot, don't know how long it would take, but I'd be willing to bet 2 bunches of bananas and 100 termites that 13/5 would come out ahead of putting a checker on the 8.
Pulling two down just wins a lot more gammons (but playing safe is not a huge mistake here)

XGID=bBBB-BC--A---C--bbbcbb----:1:-1:1:53:0:0:3:0:10

1. Rollout¹ 13/10 13/8 eq:+1.440
Player : 90.13% (G:67.34% B:0.61%)
Opponent: 9.87% (G:0.90% B:0.06%)
Confidence: &plusmn; 0.008 (+1.432<E<+1.448)
Duration: 3 minutes 17 seconds

2. Rollout¹ 13/5 eq:+1.399 (-0.041)
Player : 90.61% (G:61.78% B:0.55%)
Opponent: 9.39% (G:0.41% B:0.02%)
Confidence: &plusmn; 0.008 (+1.391<E<+1.407)
Duration: 3 minutes 44 seconds


¹ 1296 Games rolled with Variance Reduction.
Moves and cube decisions: 3 ply


eXtreme Gammon Version: 1.21
Play Against Probilities? Quote
02-14-2011 , 01:16 AM
Hey, Thanks!!
But I'm not well versed in Sanscrit. If I'm guessing right, that says....uhm....Does it say that 13/5 loses fewer games, but only by a slight margin? (If so, I would have expected a greater margin.) I would have expected the gammon thing to be as the roll out shows, but still, I'd rather win the (almost) sure single than to give it away.

BTW: I was just KIDDING!! DO NOT send me the TERMITES!!!!
Play Against Probilities? Quote
02-14-2011 , 01:33 AM
Quote:
Originally Posted by geneftw
Hey, Thanks!!
But I'm not well versed in Sanscrit. If I'm guessing right, that says....uhm....Does it say that 13/5 loses fewer games, but only by a slight margin? (If so, I would have expected a greater margin.)
Yeah pretty much. Giving him that 44 shot means that 1/36 he wins the game outright, but in the long run not getting that four point closed also becomes a problem. Sometimes he enters quickly and will get flyshots as you're coming home, sometimes when you never get to make the fourpoint naturally you increase your chances of leaving a shot during bearoff, so overall the net effect is that playing safe only wins 0.5% more games.


Another one:

Play Against Probilities? Quote
02-14-2011 , 01:58 AM
Ah, you know me, by now. At this point I become a coward. Why risk what I've already got won?

8/1

Problems MIGHT arise LATER, but leaving one open IS a problem NOW.

Part of me wants to play 7/5, 7/2, but I'm not in that gamey mood. I've got him by the throat; I ain't lettin' up.
Play Against Probilities? Quote
02-14-2011 , 02:14 AM
Quote:
Originally Posted by geneftw
Problems MIGHT arise LATER, but leaving one open IS a problem NOW.
Here all those things that might happen later, will happen often enough to be a lot worse than leaving the single shot now, but creating a very flexible position.

XGID=aCBB-BCBA----------ccbbbb-:1:-1:1:52:0:0:3:0:10


1. Rollout¹ 7/5 7/2 eq:+0.764
Player : 89.01% (G:0.88% B:0.01%)
Opponent: 10.99% (G:0.09% B:0.00%)
Confidence: &plusmn; 0.004 (+0.760<E<+0.768)
Duration: 38.9 seconds

2. Rollout¹ 8/3 7/5 eq:+0.708 (-0.056)
Player : 86.25% (G:0.94% B:0.02%)
Opponent: 13.75% (G:0.12% B:0.00%)
Confidence: &plusmn; 0.003 (+0.705<E<+0.711)
Duration: 33.6 seconds

3. Rollout¹ 8/1 eq:+0.665 (-0.099)
Player : 84.77% (G:0.52% B:0.00%)
Opponent: 15.23% (G:0.04% B:0.00%)
Confidence: &plusmn; 0.004 (+0.661<E<+0.669)
Duration: 39.4 seconds


¹ 1296 Games rolled with Variance Reduction.
Moves and cube decisions: 3 ply


eXtreme Gammon Version: 1.21


A different theme:

Play Against Probilities? Quote
02-14-2011 , 02:30 AM
That was kinda ugly, but I'm not as worried abou a 5.2sumthin' % difference as I know I should be. After all, in a game situation, I'd never be able to sense such a small difference...My flaw.

Now, this position....Hmmm....I'm more likely to hit it here, but with some hesitation, I'll still play it safe. He has a darn good chance of catching up and winning if I don't hit him, but it's in the bag for him if I hit and get the favor returned.

I think the odds are slightly in my favor withou the hit, but even more in my favor if I do hit. However, if I don't hit, the odds are more likely to STAY in my favor than if I do hit.

Drum rollout, please:

In your opinion, Am I thinking like a beginner, an intermediate, a chimp, or wut?
Play Against Probilities? Quote
02-14-2011 , 02:55 AM
Quote:
Originally Posted by geneftw

Drum rollout, please:
This is a bit tricky, I guess. You do win more games by hitting, but you also lose more gammons. One key issue is that your opponent has the cube and owning the cube in a race is very valuable. If he slowly turns the game around he'll be able to offer some pretty efficient recubes. If you hit and get hit back the cube pretty much has no value to him. With the cube unturned the plays are pretty much tied!

XGID=-BBBCaD-B----------bbccbb-:1:-1:1:15:0:0:3:0:10


1. Rollout¹ 8/3 6/5* eq:+0.263
Player : 66.10% (G:1.16% B:0.02%)
Opponent: 33.90% (G:4.79% B:0.09%)
Confidence: &plusmn; 0.004 (+0.259<E<+0.267)
Duration: 26.9 seconds

2. Rollout¹ 6/1 6/5* eq:+0.211 (-0.052)
Player : 62.35% (G:0.83% B:0.01%)
Opponent: 37.65% (G:1.94% B:0.01%)
Confidence: &plusmn; 0.003 (+0.208<E<+0.214)
Duration: 27.5 seconds

3. Rollout¹ 6/1 4/3 eq:+0.117 (-0.147)
Player : 61.89% (G:0.09% B:0.00%)
Opponent: 38.11% (G:0.06% B:0.00%)
Confidence: &plusmn; 0.005 (+0.112<E<+0.122)
Duration: 7.4 seconds


¹ 1296 Games rolled with Variance Reduction.
Moves and cube decisions: 3 ply


eXtreme Gammon Version: 1.21

Quote:
Originally Posted by geneftw
In your opinion, Am I thinking like a beginner, an intermediate, a chimp, or wut?
To be fair, I don't think any of the positions I posted are really easy.
Play Against Probilities? Quote
02-14-2011 , 01:33 PM
Quote:
Originally Posted by mute
Not saying you should never look out for jokers, but I would say if you're "often" worried about joker rolls and going out of your way to avoid them, then that's probably a mistake.

Money game, what's your play?

For this scenario, I actually like 13/8, 13/10. This gives black double 4s to hit, but when he doesn't make his 36:1 shot, I have great chances to close him out, guarantee a gammon, and shoot for the backgammon.
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