The life and death estimation gets wrong

[brynne8]

TheSgfFile.zip

genmove b
Time Limit    : 5 Sec
Playout Limit : 100000000 PO
      A   B   C   D   E   F   G   H   J   K   L   M   N   O   P   Q   R   S   T
   +----------------------------------------------------------------------------+
19:| 97  98  98  98  97  91  50  12   3   2   2   2   3   3   3   3   4   5   5 |
18:| 95  98  98  98  98  99  57   2   2   2   4   1   6   2   2   2   3   5   5 |
17:| 82  99  99  99  94  99   2   2  99   2  29  43  48   0   1   1   0   5   5 |
16:| 42   5  99   6  53  99  99  99  99  99  64  68  91   0   1   0   1   6   5 |
15:|  7   5   5   6   6  99  98  97  94  90  85  83  91  91   0   0   0   4   4 |
14:|  3  10  45  57  98  97  96  94  90  87  83  81  53   8   9   3   7   1   2 |
13:|  0   0 100  92  96  97  96  95  88  74  81  91  53   8   9   7   7   1   1 |
12:|  0   0 100  97 100  98  98  99  99  59  11  50  44   8   9   9   0   1   2 |
11:|  0   0 100 100 100 100  98  96  99  63  30   2   6  11   0   4   0   2   6 |
10:|  0   0   0   0 100  98  98  96  99  82  59  50   0   3   0   0   1   5   9 |
 9:|  0   0 100 100 100 100 100  96  96  99  99  99  46   0   0   0   0   0  23 |
 8:|  1   1   1 100  99  99  98  98  96  99  96  99  68  50   0   0  89  89  60 |
 7:|  2   1   1 100 100 100 100  98  96  99  96  99  99  99   0  77  69  86  84 |
 6:|  5   4   1   1 100 100 100  99  96  96  96  96  96  99  50  69  89  92  93 |
 5:|  9  12  42  52 100 100  96  96  96  96  96  96  99  99  99  99  99  99  97 |
 4:|  9   9  99  99  99  99  99  96  96  96  96  96   0  99   0  56   1   1  97 |
 3:| 10  11  11  99  99  99  99  96  96  96  96  96   0  99   0   0  12  95  95 |
 2:| 10  10  70  99  96  96  96  96  96  96  96  96   0   0   0   0   0   0  95 |
 1:| 22  57  84  99  99  99  99  96  96  96  96  96  26   0   0   0   0   0  21 |
   +----------------------------------------------------------------------------+
BLACK+38.5
Best Sequence : L13(BLACK : 12698/13563)->K13(WHITE : 404/5171)->K14(BLACK : 2698/2872)->J13(WHITE : 72/945)->K12(BLACK : 447/474)->J14(WHITE : 8/146)->J15(BLACK : 87/90)
Prisoner(Black) : 2
Prisoner(White) : 4
Move : 210
     A B C D E F G H J K L M N O P Q R S T
   +---------------------------------------+
19:| + + + + + + + + + + + + + + + + + + + |
18:| + + + + + B + W W W + W + + + + + + + |
17:| + B B B + B W W B W + + + W + + W + + |
16:| + W B W + B B B B B + + B W + W + B + |
15:| + W W W W B + + B + + + B B W + W + + |
14:| + + + + B + + + W B + + + W B + B W + |
13:| + W B + + + + + W W B B + W + + B W + |
12:| + W B + B + + B B B W + + W B B W + + |
11:| + W B B + B + W B + + W + B W + W + + |
10:| + W W W B W + W B + + + W + W + + + + |
 9:| + W B B B B B W W B B B + W + + W W + |
 8:| + + W B + + W B W B W B + + W W B B + |
 7:| + + W B + B B + W B W B B B W B + + + |
 6:| + + W W B + B + W W W W W B + + + + + |
 5:| + + + + B B W W W B W W B B B B B B + |
 4:| + W B B + W B W W B B B W B W + W W B |
 3:| + + W B B B B W B B W B W B W W + B + |
 2:| + W + B W W W W W B W B W W + W W W B |
 1:| + + + B B B B W W B + B + W + W + W + |
   +---------------------------------------+
All Playouts       :    17854
Pre Simulated      :        0
Win                :    16679
Thinking Time      :    5.001 sec
Winning Percentage :  93.4188%
Playout Speed      :     3570 PO/sec 
= L13

At this position, black is already dead, but it still thinks the black group is alive and the winning percentage is high.

[zakki]

Ray seldom plays capture move (white N1), and self atari moves (white L2 and L2).
This causes the white J1 stones often die before black K1 stones die.

[kobanium]

sim_log.zip
Ray sometimes plays white N1. But it's difficult for Ray to throw in L2 or L3 after capturing stones (L2 and L3).
The file has 10 Ray's simulation samples. It shows L2 and L3 have low scores.
I try to modify Ray's simulation.

[zakki]

FYI, Rn is using simple snapback detection in simulation.
Results of 1000 games with 5000po are 49.6% (±1.6). Perhaps more generic way is needed to capture n-moku nakade etc.
zakki@7bde059