RE: computer-go: transpositions (less unclear?)

[met@xxxxxxxxxxxxxx]

Anders Kierulf wrote:
> Smart Go modifies the hash code for all moves that capture stones.
> The hash modification is based on:
> (a) the move number, and
> (b) the stones that got captured.

I have now tested your suggestion!
What other properties do you include into the hash code?

I asume that  you also need to include the illegal points as
to make the above to work. (I include the board layout, the
player at move) (I also include some properties depending
on my implemetation. That is if the player at move is aloved
to pass or not and the number of available ko-threats)

My first test showed a drastic increase of the number of
evaluated positions (vs ignoring super-ko) ie the number
of transpositions decreased sometimes up to 20-30 times.

I think I have an idea of when the suggested hashcoding
failes. This is one of the hashing failures reported by my
program:

Variation one:

Black at move:
+ + O + O + # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[1] = 6-1
White at move:
+ + O + O # # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[2] = 2-1
Black at move:
+ O O + O # # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[3] = 4-1
White at move:
+ O O # + # # -
# O + # + # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[4] = 5-2
Black at move:
+ O O # + # # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[5] = 3-2
White at move:
+ O O # + # # -
# O # # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

Status: White can live

Variation two:
Black at move:
+ + O + O + # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[1] = 4-1
White at move:
+ + O # O + # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[2] = 2-1
Black at move:
+ + O # O + # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[3] = 6-1
White at move:
+ O O # + # # -
# O + # + # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[4] = 5-2
Black at move:
+ O O # + # # -
# O + # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

ply[5] = 3-2
White at move:
+ O O # + # # -
# O # # O # # -
# O O O # # # -
# # # # = - - -
- - - - - - - -

Status: White can't live

Thanks again.

Reagrds,
Mikael Thulin