Game 1, move 5: Herd to move 4-4

[diane]

A few obvious moves..

After the 2-1, Herd rolled 6-1 and moved 13/7, 8/7

r_monk rolled 2-1 and made the 4 point, now Herd has a 4-4 to place, which has a few alternative moves to think about.



2GbMASFmtoUDIA:cAmyAAAAAAAA

[ah_clem]

Spoiler

The double hit is intriguing, but if we're going to double hit 13/5*/1* 13/9 may be a better way to do it.

 13/5(2)* makes a five prime, the three best homeboard points, and puts a checker on the roof - that's a lot for one move.  If we're not going to hit twice, making the five point is mandatory here, and 13/5(2)* is the only sensible play that makes the 5.  The other choice prematurely moves a checker onto the four and gives up the 5-prime.

So, which way to go: hit twice or build a prime?  It's ususlly better to hit once and make a homeboard point than to hit twice, so that favors 13/5*(2) over my double hit suggestion.  The other double hit makes a homeboard point in addition to hitting twice, so that maxim doesn't help us choose here.  We need to decide which is better - having a five prime with one on the bar and one on the ace with the three best homeboard points, or hitting twice and having a broken blockade?  What tips it for me is our blot on the ace after the double hit.  White has a good blockade of his own so offering a hit is not what we want to do.  Besides, it's too early to start burying checkers.

Our main liability after either play is our runner, and getting  it home is a timing thing - a solid blockade on our side of the board has to help that, assuming we can hold it.  Being hit helps our timing, so the 5 prime acts as an "escort" for the runner.

This may be moot, as we might have a cash next move. (Diane - don't forget to ask for a double before our next roll)   One possible argument in favor of the double hit is that it may give more takable gammonish possibilities than the stolid prime making play, and if we can get him to take a gammonish cube, that's good in these short matches.  But I'm skeptical about making an "inferior" play in order to get the opponent to take so I'll stick with 13/5(2)*.

[close]

[ah_clem]

So, anybody else want to weigh in on why their choice is their choice?

[stog]

Spoiler

7/3 (2), 9/5*/1* let's go for it!

[close]

[diane]

Spoiler

7/3 (2), 9/5*/1* let's go for it!

[close]

I'm with you stog!! but we certainly have a split vote here again!

[ah_clem]

Spoiler

  Here's another way to look at it:

After the double hit, his good return numbers are any 1 plus 55, for a total of 12 rolls that turn the game around.

After 13/5(2)*, his good numbers are 3-2 3-1 3-6 and 1-1.  That's only seven, and only 3-6 really turns the game around as he'll still have two checkers stuck behind a 5 prime.

We've probably got a cash unless he rolls the game-changer.  Do we give him a 1/3 chance or a 1/18 chance?

[close]

[diane]

Spoiler

But he'll have two on the bar..and that's better by far..... isn't it...

[close]

[ah_clem]

Spoiler

But he'll have two on the bar..and that's better by far..... isn't it...

Not if you prematurely bury a checker, give him a direct shot, and leave a blockade that resembles swiss cheese in order to do it.

[close]

[socksey]

Spoiler

What about 9/5*/1*, 13/9 (2)?

[close]

socksey



"About morals, I know only that what is moral is what you feel good after and what is immoral is what you feel bad after." - from American writer Ernest Hemingway born in 1899

[ah_clem]

Spoiler

What about 9/5*/1*, 13/9 (2)?

It's the same move that I suggested earlier: 13/5*/1* 13/9.  I rejected it in favor of  13/5(2)* because it's usually better to hit and make a homeboard point than to hit twice if you have the choice between the two.  I think it's playable, and doesn't rush as many checkers too far forward as the other double-hit, but since it doesn't make the fourth homeboard point it's probably inferior.
We're probably cashing this one next turn anyway...

[close]

[socksey]

Oop!  Guess I misread that one, ah_clem.     Maybe that choice should have been included, tho.   

socksey



"A serious writer is not to be confounded with a solemn writer. A serious writer may be a hawk or a buzzard or even a popinjay, but a solemn writer is always a bloody owl." - from American writer Ernest Hemingway born in 1899

[ah_clem]

Oop!  Guess I misread that one, ah_clem.     Maybe that choice should have been included, tho.   

You can always ask for a voting option to be added.  If the active moderator isn't around, any other mod can add it.  You might even have the rights yourself.

There's a balance to be struck between offering an overwhelming number of options (Trice claims to have constructed a position that had several thousand possible moves) and leaving off some potentially good ones that people may want to vote for.  It's probably better to err on the "less" side and add as necessary. 

[diane]

You might even have the rights yourself.

Yes, all moderators can do it...and Socksey has opened the 'edit poll' option on other matches, but not as yet made any changes.

Moves like this, there are as you say, a lot of possibilities and too many consfuses people and splits the vote, so you have 9 votes for 9 moves.  Dorbel has suggested that we dont put any options in and let people post their own...I cant say as I agree with that, as newbies are here to learn.  What you can infer though, is that if I haven't put an option in there, it wasn't in the top 5 moves suggested by gnu - or had an error rate greater than 5ish.
Gnu has been known to be wrong though, so you can always argue for any move if there is reason for it 

[ah_clem]

rollout

Spoiler

gnubg 0-ply reports that the top two vote getting plays are fairly close but blunders compared to the third place move.

Why this play is so much better?   In retrospect, it's similar in theme to 13/5(2)*, but it keeps the midpoint and exposes one less blot.  Anybody have any other ideas?  Is it a timing thing?

FWIW, 2-ply analysis has 13/5(2)* ahead of the double hit and not as much of a whopper as the rollout.



///////////////// 0 ply rollout //////////////////////////////

   1. Rollout          13/5* 9/5 8/4                Eq.:  +0.685
       0.634 0.388 0.015 - 0.366 0.075 0.003 CL  +0.598 CF  +0.685
      [0.002 0.002 0.001 - 0.002 0.001 0.000 CL   0.006 CF   0.013]

    2. Rollout          9/5*/1* 7/3(2)               Eq.:  +0.575 ( -0.110)
       0.596 0.396 0.009 - 0.404 0.109 0.006 CL  +0.516 CF  +0.575
      [0.002 0.002 0.001 - 0.002 0.001 0.001 CL   0.006 CF   0.014]

    3. Rollout          13/5*(2)                     Eq.:  +0.558 ( -0.127)
       0.609 0.359 0.017 - 0.391 0.081 0.005 CL  +0.515 CF  +0.558
      [0.002 0.002 0.001 - 0.002 0.001 0.001 CL   0.006 CF   0.015]
        Full cubeful rollout with var.redn.
        1296 games, Mersenne Twister dice gen. with seed 896490702 and quasi-random dice
        Play: 0-ply cubeful prune [expert]
        Cube: 0-ply cubeful prune [expert]

/////////// 2-ply analysis //////////////////

    1. Cubeful 2-ply    13/5* 9/5 8/4                Eq.:  +0.778
       0.651 0.396 0.014 - 0.349 0.073 0.003
        2-ply cubeful prune [world class]
    2. Cubeful 2-ply    13/5*(2)                     Eq.:  +0.734 ( -0.044)
       0.639 0.372 0.013 - 0.361 0.071 0.003
        2-ply cubeful prune [world class]
    3. Cubeful 2-ply    9/5*/1* 7/3(2)               Eq.:  +0.675 ( -0.103)
       0.605 0.401 0.011 - 0.395 0.102 0.005
        2-ply cubeful prune [world class]

[close]

[socksey]

Yes, all moderators can do it...and Socksey has opened the 'edit poll' option on other matches, but not as yet made any changes.

Ummm........recalling the last and only time I changed anything on your posting and got my hand slapped soundly..........I believe it was a spelling correction done before you were appointed global moderator.........I wouldn't dare to change anything you have posted, my dear, except, of course, it was something against the board policy.     No!  Actually, I was hoping you would offer that option yourself.     But, Noooooooooooo.  That's OK, tho.  As you wish.

socksey



"The greater the power, the more dangerous the abuse." ~ Edmund Burke ~

[diane]

Ummm........recalling the last and only time I changed anything on your posting and got my hand slapped soundly..........I wouldn't dare to change anything you have posted, my dear, except, of course, it was something against the board policy.     No!  Actually, I was hoping you would offer that option yourself.     But, Noooooooooooo.  That's OK, tho.  As you wish.

Hmm..so you dont recall this discussion then..

Ummmmmmmmm...........I tried editing, but I didn't see an option for changing a vote, only one for setting them all back to zero.......so, if you don't mind, tell me how I have the power, please?   

You can re read it here..

http://www.fibsboard.com/fibsboard-forum-match-4/game-4-move-24-forum-5-5/msg21877/#msg21877

When this started, I put in a statement 'you can add options or ask for them added' on each and every poll..I have stopped posting that now, as most people seem to have the hang of it. And, given the previous discussion above, I thought you in particular would now know how to do it.

The time difference for me now means I am genuinely not around at times and able to respond to requests to change things.  By the time I come back to check the progress of a poll, it is almost over and if a decision is clear cut, I wont start adding options at that time.  If you do see something you want in that isn't..you have express permission from me to add it..how's that   

But try to restrain yourself on correcting spelling and grammar...we have different views on that 

[socksey]

diane,

Your reference was to my changing a vote, not for adding options.  I'm sorry if I caused you added time. 
I'm also sorry, I am too dumb to understand you.

socksey



"Be a philosopher but, amid all your philosophy be still a man." - David Hume

[diane]

diane, Your reference was to my changing a vote, not for adding options. 

My reference was to you extending a voting period...or editing a poll...I was quite clear in another post to you on that thread...

I guess that is the other problem with a short voting period, not everyone gets here.

For future reference - you have the power to open the poll and give it a bit longer - so you could have fixed it.

[Zorba]

rollout

Spoiler

gnubg 0-ply reports that the top two vote getting plays are fairly close but blunders compared to the third place move.

Why this play is so much better?   In retrospect, it's similar in theme to 13/5(2)*, but it keeps the midpoint and exposes one less blot.  Anybody have any other ideas?  Is it a timing thing?

FWIW, 2-ply analysis has 13/5(2)* ahead of the double hit and not as much of a whopper as the rollout.

[close]

Spoiler

8/4 for the last four instead of 13/9 leaves clearly less return shots. Since there could be a strong cube coming up if r_monk doesn't perform, extra return shots are even worse than normal for your equity. Note how leaving the blot on 8 gives monk just a 5-3 from the bar ("duplicated" with the open points), the blot on nine gives 3-6 and 5-4. Not to mention the extra blot on the midpoint, giving 1-1, 3-1 and 5-1 for another 5 shots.

As for the difference between your 0-ply rollout and 2-ply evaluation: since a cube decision is likely on the next turn, having 0-ply making that cube decision as in your rollout coulld be unreliable. Try using 0-ply for checker play and 2-ply for cube and see if it changes anything.

In any case, this roll creates a very volatile position with lots of cubes thrown, so small inaccuracies by the bot could get magnified here, especially if the bot is not cubing correctly.

[close]

[ah_clem]

8/4 for the last four instead of 13/9 leaves clearly less return shots.  ... Note how leaving the blot on 8 gives monk just a 5-3 from the bar ("duplicated" with the open points), the blot on nine gives 3-6 and 5-4. Not to mention the extra blot on the midpoint, giving 1-1, 3-1 and 5-1 for another 5 shots.

Hmmmm.  5-4 is not a hit from the bar, it's a dance. 1-5 is likewise not a hit (unless you count on him hitting loose in his homeboard and exposing two blots.) So that's only four three extra shots, not ten nine.  

I'm sure that four extra shots is part of the picture, but I've done some thinking about this position and here's why I think 8/4 is superior to 13/9:

After making the five prime, our next objective should be making the three point to keep him from anchoring there and to move towards a closeout (slotting the point behind the 5 prime is usually the right thing to do, but here we want to prevent the anchor and that's more important than simply building a full prime) .  Both moves aim three builders at the three point, but the checker on the nine is 6 pips away and sixes are needed to escape the back man.  Thus 13/9 duplicates sixes.  This duplication is what makes 13/9 inferior.

This, combined with the four extra shots makes it more clear.  Holding the midpoint is probably worth something too.  I'm still not sure whether there's some timing benefits one way or the other.



(dispensing with the spoiler tags as this position was decided a long time ago...)