bug-gnubg
[Top][All Lists]

## Re: [Bug-gnubg] Some Questions about rollouts.

 From: Joern Thyssen Subject: Re: [Bug-gnubg] Some Questions about rollouts. Date: Fri, 1 Nov 2002 23:51:07 +0000 User-agent: Mutt/1.4i

```On Fri, Nov 01, 2002 at 04:21:29AM -0500, address@hidden wrote

> Regarding 33% speed. How is this implemented? Could you tell me the maths
> behind it in not too technical terms please :-)

Normal 2-ply evaluation:

equity=0
Loop over 36 rolls
find best move for roll
equity = equity + 1-ply equity for resulting position
End loop

final 2-ply equity = equity/36

The 1-ply equity is defined analagously:

equity=0
Loop over 36 rolls
find best move for roll
equity = equity + 0-ply equity for resulting position
End loop

final 1-ply equity = equity/36

Reduced 2-ply evaluation:

equity=0
Loop over 36 rolls
find best move for roll
equity = equity + reduced 1-ply equity for resulting position
End loop

final 2-ply equity = equity/36

The reduced 1-ply equity is as:

equity=0
Loop over reduced set of rolls
find best move for roll
equity = equity + 0-ply equity for resulting position
End loop

final reduced 1-ply equity = equity/number of rolls

For example, for a 33% reduced 2-ply evaluation the reduced set of rolls
contains 7 rolls whereas a 66% reduced 2-ply evaluation would contain 14
rolls.

Jørn

--
Joern Thyssen, PhD
Vendsysselgade 3, 3., DK-9000 Aalborg, Denmark
+45 9813 2791 (private) / +45 2818 0183 (mobile) / +45 9633 7036 (work)
Note: new mobile number!

```