This is a position where I need a little help.
(Gnu Position ID: i/0RBgC0vdoAAA)

Pip count: Brown 91, White 98




This is what Gnu gave as a 4-ply hint:



There is hardly any difference in equity between the moves, but I cannot help but feel that the play here does actually make a big difference.

So my first question is whether or not I should trust Gnu in this type of position. Or rather, I should ask in which type of positions Gnu is trustworthy?

Secondly, the move itself. I can bring two checkers home, loading my 6-point, or I could, in the other extreme, completely clear my 6 point - neither would make any real significance to my pip-count, but simply I cannot believe that the two strategies are the same in equity.

Which strategy would be best, and why?

White - Pips 0

Black - Pips 79
Diagram 1. Ideal Bear-in Position in a Non-contact Race


Black - Pips 70
Diagram 2. Woolsey's Wedge

The two positions above share a distinctive wedge-shape that is easy to remember. Both are ideal racing positions. I always aim for some sort of hybrid of them during the bear-in phase of a non-contact race.

One somewhat surprising feature of the diagrams above is that it is OK to have a pretty large stack on the 6pt, provided the rest of the wedge is in place too. That tell’s you that crossing over with your aces is probably a good idea. To my eye, it was also plain that 6/5 was going to be part of the play. You need that to build your wedge.

What is not obvious from the diagrams above is how seldom you need to have *any* checkers on the 7pt during a bear in. In a way, putting checkers on the 7pt during the bear in is like putting checkers on the 1pt during the bear off. Wastage is implied, because often those checkers will crossover or be borne off using a number larger than 1.

One of the top priorities is to keep the outside checkers diversified during the bear in. That way, it is easier to build the wedge inside. In many cases, spreading out the outside checkers will be more important than crossing over, especially when crossing over puts a checker in the wrong place.

Putting it all together, the first two aces were easy to play: 7/5. Next, I took a look at the pip count, and noting that you are behind, I opted for the crossover: 8/6. Five checkers on the 6pt is not too many. Since there is no play that does much better at diversifying the outside checkers, and noting that leaving a checker on the 7pt was a low priority, I felt that this play might also be best when tied or ahead in the race.

Here is the EPC data for your position:

For more info on this sort of position, see this thread: http://forumserver.twoplustwo.com/13...-bear-1403586/

Hope this helps.

Mike

Diagram 1 in Mike's post ("Trice's Tower") is the ideal bearoff position for 15 checkers in the home board and a pip count of 79. Diagram 2 ("Woolsey's Wedge") is ideal for 15 checkers and a pip count of 70. They are worth committing to memory.

Which one you're aiming for depends on the placement of your outside checkers. If they are far back in your outer board (say on the 11, 10, and 9-points) then you want to aim for Trice's Tower. If they're mostly closer to home (say on the 7, 8, and 9-points) then go for Woolsey's Wedge. After Mike's play 7/5 8/6, which looks right with a 1-1, your last 4 checkers are on the 9 and 10-points, so I'd be aiming to create something close to Trice's Tower.

Thanks guys - very helpful replies.

It is surprising that the stack on the 6-point is okay, but the wedge diagrams make a lot of sense. Also, they are easy to remember, because the one is 7-5-3 and the other is 5-4-3-2-1. This has been a very useful thread. Much appreciated.

great replies.

Nice to have a name for it.

Mike

Okay, here's a follow-on problem, but this time, I'm considering cube action.
(Gnu Position ID: 7L4PAADa/Q4AAA)

XG says double, gnu says don't double!

Firstly, what should the win% be to double. Secondly, If I consider the wedge diagrams, I definitely have a superior wedge.With a win% of 0.701, I would say this is a clear double, but Gnu disagrees, and XG says it's close.

Should I double?

[IMG]http://s10.************/nfo8239nd/Flashcard_Position_ID_000905_Gnu_Bg_3_ply_Eval.png[/IMG]

Above, we have GnuBg recommending Double/Take!

Interesting little hiccup. When you get close evals like these, it's time to do a rollout! Even before starting, however, we know that this is a marginal double at best. Rollouts in both GnuBg and XG confirm that it is not even that. This is a no-double, for sure.

Because this is a medium- to low-volatility position, you can wait before cubing. 70% winning chances is not quite good enough to make an initial double in a low-volatility situation. If neither side rolls a large doublet, then the pip count will seesaw back and forth. If you pick up a pip or two on the next exchange, then you will probably have a cube.

Mike