Re: computer-go: 5x5 Go is solved

["Andrew Derrick Balsa" <andrebalsa@xxxxxxxxxxxxxxxxxx>]

Hi Erik,

Congratulations!

On Sun, 20 Oct 2002 15:27:04 -0100, "Erik van der Werf"
<E.vanderWerf@xxxxxxxxxxxxxxxxx> said:
> Yesterday my program solved 5x5 Go starting with the first move in the
> centre. As was expected it is a win for the first player with 25 points
> (the whole board belongs to black).
> 
> I used an iterative deepening Alpha-beta search (PVS) with:
> - Transposition tables (2-deep replacement scheme, 2 x 2^24 entries)
> - Enhanced transposition cut-offs
> - Symmetry lookups in the Transposition table
> - 2 killer moves
> - History heuristic
> - Benson's algorithm for unconditional live (extended with unconditional
> territory)
> - Heuristic evaluation for positions that are not fixed by benson

Could you please expand on each of these?
> 
> The solution was found at 22 ply deep (23 for the empty
> board).(searching 4.472.000.000 nodes in about 4 hours on a P4 2.0Ghz)

That gives us 310k nps, or one node every 3 microseconds; very efficient
coding. In what language did you code your program? Do you plan to
release it?

It would be nice to have the complete solution in the form of a table,
that one could download for future use.

Regards,
--
Andrew D. Balsa
andrebalsa@xxxxxxxxxxxxxxxxx

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