[gnugo-devel] strategic effect

[Arend Bayer]

As I said I tried tweaking the strategic effect valuation a little. The
results look encouraging, 22 PASSes and 10 FAILs, with four of the tests
in safety.tst solved. It is not yet finished, as I will try to do some
fine-tuning (I also haven't looked at the failures yet).

As that might take some time, I am posting this preliminary version.

The patch itself is extremely simple, see below.

Arend

./regress.sh . nngs1.tst
35 unexpected PASS!
48 unexpected FAIL: Correct 'R16', got 'F15'
50 unexpected PASS!
52 unexpected PASS!
./regress.sh . strategy.tst
20 unexpected PASS!
./regress.sh . ego.tst
8 unexpected PASS!
./regress.sh . strategy2.tst
70 unexpected FAIL: Correct 'M15|J15|N16|J16', got 'C15'
83 unexpected PASS!
91 unexpected PASS!
94 unexpected FAIL: Correct 'A2', got 'J2'
./regress.sh . niki.tst
4 unexpected PASS!
./regress.sh . trevorc.tst
600 unexpected PASS!
1080 unexpected PASS!
./regress.sh . global.tst
5 unexpected FAIL: Correct 'O4', got 'F5'
./regress.sh . arend.tst
35 unexpected FAIL: Correct 'H17|J19', got 'F15'
38 unexpected FAIL: Correct 'O5', got 'O17'
./regress.sh . 13x13.tst
28 unexpected FAIL: Correct 'L10', got 'E3'
41 unexpected PASS!
./regress.sh . trevord.tst
120 unexpected FAIL: Correct 'B9', got 'F7'
870 unexpected PASS!
./regress.sh . strategy4.tst
200 unexpected FAIL: Correct 'P6|P7|Q7|S18', got 'Q8'
./regress.sh . nngs2.tst
240 unexpected FAIL: Correct 'F17', got 'B14'
290 unexpected PASS!
400 unexpected PASS!
./regress.sh . nngs3.tst
140 unexpected PASS!
290 unexpected PASS!
320 unexpected PASS!
./regress.sh . strategy5.tst
277 unexpected PASS!
./regress.sh . safety.tst
1 unexpected PASS!
2 unexpected PASS!
4 unexpected PASS!
7 unexpected PASS!


Index: engine/move_reasons.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/move_reasons.c,v
retrieving revision 1.99
diff -u -r1.99 move_reasons.c
--- engine/move_reasons.c       9 Oct 2002 18:36:23 -0000       1.99
+++ engine/move_reasons.c       10 Oct 2002 19:26:13 -0000
@@ -1983,6 +1983,17 @@
     move[pos].randomness_scaling = scaling;
 }

+
+/* Returns a capped effective size of the dragon at pos for use in
+ * the strategic effect.
+ */
+float
+strategic_effective_size(int pos)
+{
+  float eff = dragon[pos].effective_size;
+  return ((20.0 * eff) / (20.0 + eff));
+}
+
 /*
  * Local Variables:
  * tab-width: 8
Index: engine/move_reasons.h
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/move_reasons.h,v
retrieving revision 1.25
diff -u -r1.25 move_reasons.h
--- engine/move_reasons.h       9 Oct 2002 18:36:23 -0000       1.25
+++ engine/move_reasons.h       10 Oct 2002 19:26:14 -0000
@@ -203,6 +203,8 @@
                         int move_reason_type, char changed_stones[BOARDMAX],
                         float *effective_size);

+float strategic_effective_size(int pos);
+
 /*
  * Local Variables:
  * tab-width: 8
Index: engine/value_moves.c
===================================================================
RCS file: /cvsroot/gnugo/gnugo/engine/value_moves.c,v
retrieving revision 1.61
diff -u -r1.61 value_moves.c
--- engine/value_moves.c        9 Oct 2002 18:36:23 -0000       1.61
+++ engine/value_moves.c        10 Oct 2002 19:26:26 -0000
@@ -2209,13 +2209,13 @@
         * dragon safety alone is not enough. The question is whether
         * the dragon is threatened by the move or not.
         */
-       this_value = (dragon[aa].effective_size
+       this_value = (strategic_effective_size(aa)
                      * (1.0 - dragon_safety(aa, 1)));

        /* To prefer good connections and cuts, we lower this value
         * somewhat.
         */
-       this_value *= 0.75;
+       this_value *= 1.8;

        /* No strategical attack value is awarded if the dragon at (aa)
         * has an adjacent (friendly) critical dragon, which is not