[Computer-go] Exploration formulas for UCT

[Aja]

For Erica, it's almost the same with Many Faces, except that I use progressive_bias not mfgo_bias (of course, if David send the details of mfgo_bias to me, I will use :)

I compute beta by David Silver's formula (70 elo stronger than the original one) and UCT_C is set to 0.6. I can't get any good result from smaller UCT_C.

Aja

  ----- Original Message ----- 
  From: David Fotland 
  To: computer-go at dvandva.org 
  Sent: Sunday, January 02, 2011 4:18 AM
  Subject: [Computer-go] Exploration formulas for UCT


  It would be interesting to see the actual formulas used for choosing the more to try in the tree part of the search.

   

  For Many Faces, it is:

   

  (1 – beta) * (win_rate + 0.45 * sqrt( ln(parent_visits) / child visits)) +

  beta * rave_win_rate + mfgo_bias 

   

  beta is the old Mogo formula of sqrt(500/(500 + 3 * parent_visits))

   

  A child with no visits has a win_rate of 1.1.  Otherwise there is no win_rate bias.

   

  rave wins and visits are strongly biased when moves are generated using various rules and information from the mfgo move generator (in a range of 10% to 90% win rate, with hundreds to thousands of visits).

   

  mfgo_bias is unchanging, per move, within a range of about +-2%, based on mfgo’s move generator’s estimate of the quality of the move.

   

  Does anyone else want to share?

   

  David

   

  From: computer-go-bounces at dvandva.org [mailto:computer-go-bounces at dvandva.org] On Behalf Of Fuming Wang
  Sent: Saturday, January 01, 2011 9:00 AM
  To: Aja; computer-go at dvandva.org
  Subject: Re: [Computer-go] Fwd: News on Tromp-Cook ?

   

  Hi Aja,



  On Sun, Jan 2, 2011 at 12:16 AM, Aja <ajahuang at gmail.com> wrote:

  Hi Fuming,

   

  Most of the current strong programs are using UCT combined with RAVE (a kind of AMAF). The formula is like this (there are many variants),

   

  C*RAVE+(1-C)*UCT


  This has been my understanding. However, I am surprized to find out that people have been setting C close to one, according to Petr and Oliver's postings, which is essentially AMAF. MF apparently is doing something different.

  Fuming



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