Tuesday, December 29, 2015

New books for iCE

I finally extended my book building framework to include iCE performance data for certain lines. In the past the database just consisted of lines played by strong programs. Lines that were played successfully more often received a higher chance to be selected in game play.

I now added win/draw/loss statistics that I collected when two similar versions of iCE played each other. For the starting position it now looks like this


FEN: rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1
EndGame Id: UNKNOWN

Played moves :

DataBase Content:

No    Move      Prob     Played     Perf %    Wins      Draws     Losses
------------------------------------------------------------------------
 1    e2e4      44       38.031     51.59    25.021    41.387    22.208
 2    d2d4      41       36.392     53.22    24.494    40.629    19.076
 3    c2c4       8        7.283     53.06     8.104    13.541     6.388
 4    g1f3       6        5.019     52.99     8.173    13.948     6.463
 5    g2g3       1          487     51.69       989     1.543       874
 6    b2b3       0          298     51.93       250       417       216
 7    b2b4       0          281     45.18        18        39        26
 8    f2f4       0          275     45.80       116       259       161
 9    b1c3       0          201     50.78       105       182        99
10    c2c3       0          132     75.00         7         4         1
11    e2e3       0          124     56.00        25        34        16
12    g2g4       0           13      0.00         0         0         0
13    d2d3       0           12     56.82         7        11         4
14    a2a3       0            3     42.65         6        17        11
15    h2h3       0            2      0.00         0         0         0
16    f2f3       0            1      0.00         0         0         0
17    a2a4       0            1      0.00         0         0         0

Book Content:

No    Move      Prob
--------------------
 1    e2e4      44
 2    d2d4      41
 3    c2c4       8
 4    g1f3       6
 5    g2g3       1


When we dive into one line, eg the sicilian after 1. e4 c5 we come to

FEN: rnbqkbnr/pp1ppppp/8/2p5/4P3/8/PPPP1PPP/RNBQKBNR w KQkq - 0 2
EndGame Id: UNKNOWN

Played moves : e2e4 c7c5

DataBase Content:

No    Move      Prob     Played     Perf %    Wins      Draws     Losses
------------------------------------------------------------------------
 1    g1f3      86       12.764     51.21     9.042    14.326     8.279
 2    b1c3       6          981     48.10       925     1.713     1.066
 3    c2c3       6          935     52.21       678     1.295       566
 4    g1e2       1          184     49.87        97       181        98
 5    g2g3       1           88     45.18        27        49        38
 6    f2f4       0           74     46.33       108       239       144
 7    b2b3       0           71     46.18        63       116        83
 8    d2d4       0           53     43.94        29        58        45
 9    d2d3       0           51     46.33        92       157       119
10    c2c4       0           33     38.10         2        12         7
11    a2a3       0           17     44.64         8         9        11
12    b2b4       0           15     37.50         1         4         3
13    f1c4       0           10     25.00         0         1         1
14    b1a3       0            9     55.92        23        39        14

Book Content:

No    Move      Prob
--------------------
 1    g1f3      93
 2    c2c3       7


The database shows that the move 2. Nc3 is a common variation but iCE scores less than 50% with it, which is a bad score for white. So this move is now no longer copied into the book. If however iCE is playing black and the opponent selects this move it still knows how to continue

FEN: rnbqkbnr/pp1ppppp/8/2p5/4P3/2N5/PPPP1PPP/R1BQKBNR b KQkq - 1 2
EndGame Id: UNKNOWN

Played moves : e2e4 c7c5 b1c3

DataBase Content:

No    Move      Prob     Played     Perf %    Wins      Draws     Losses
------------------------------------------------------------------------
 1    b8c6      65          566     51.30       555       862       505
 2    d7d6      22          192     52.18       383       601       326
 3    e7e6       9           77     52.51       145       253       119
 4    a7a6       2           18     48.60        40        93        45
 5    g7g6       2           17     50.00        18        37        18
 6    b7b6       0            2      0.00         0         0         0
 7    g8f6       0            1      0.00         0         0         0

Book Content:

No    Move      Prob
--------------------
 1    b8c6      65
 2    d7d6      22
 3    e7e6       9
 4    a7a6       2
 5    g7g6       2


 I think it makes sense to build the books this way, it probably does make a difference ELO wise but anyway as a human I try to avoid lines I don't feel comfortably with also.