Author: Tim Foden
Date: 04:12:19 05/11/03
Go up one level in this thread
On May 11, 2003 at 06:08:23, Geoff wrote:
>Hi
>
>Seems several of us are currently struggling with adding Null move logic to our
>code. I have added it to what started off as TSCP.
>
>My first attempt was pretty hopeless.
>
>Added new features were ;-)
>
>1) Failure to return from search in some positions
>2) Timeout code was broken as the taking back of moves after a timeout now went
>wrong.
>3) Depth extension if in check now causes something to go wrong too.
>
>Anyways I have been tinkering and trying to fix it. Null move is a small amount
>of extra code but very tricky to debug and understand. Least it is for me !
>
>I am not sure I have got it totally fixed now, but it seems to be working OK at
>the moment (only a couple hours of testing)
>
>The results are amazing, so good in fact I am wondering if I am doing too many
>Null moves and potentially adding a bug? A time of 324.6 Secs drops to 9.6 Secs.
>Is this plausible ?
324.6 / 9.6 = 33.8125
Here are runs of Green Light, with null move switched off, and then with null
move switched on. Time for 8 ply drops from 3.7 secs to 0.14 secs
3.7 / 0.14 = 26.429
So it looks fine in this position. :)
Cheers, Tim.
-----
Analysis, GLC3, 24MB Hash, AXP 1.47GHz:
Null move off:
Ply Time Score Nodes Principal variation
1 0.000 +2.643 10 Qxf4 {++}
1 0.000 +3.253 11 Qxf4
1 0.000 +3.253 96 Qxf4
2 0.000 +3.199 170 Qxf4 Kg8
2 0.000 +3.653 268 Qxf7+ {++} Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+
Bf6 5. Rh7+ Kf8 6. Rxc7
2 0.020 +7.311 539 Qxf7+ Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rh7+ Kg8 6. Rxc7 Bxg5
2 0.020 +7.311 702 Qxf7+ Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rh7+ Kg8 6. Rxc7 Bxg5
3 0.030 +7.711 1190 Qxf7+ {++} Kxf7 2. Rxh7+ Kf8 3. Rxf4+ Bf6 4. Rxc7
3 0.030 +8.537 1837 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+ Bf6
5. Rxc7
3 0.030 +8.537 3945 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+ Bf6
5. Rxc7
4 0.030 +8.937 4048 Qxf7+ {++} Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+
Bf6 5. Rxc7 Re8 6. Bxe8
4 0.030 +Mate07 9822 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
4 0.040 +Mate07 15973 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
5 0.060 +Mate07 36703 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
5 0.090 +Mate07 81320 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
6 0.150 +Mate07 154152 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
6 0.261 +Mate07 303205 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
7 0.471 +Mate07 583163 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
7 1.032 +Mate07 1338270 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
8 1.713 +Mate07 2162885 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
8 3.706 +Mate07 4752725 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
Null move on:
Ply Time Score Nodes Principal variation
1 0.000 +2.643 10 Qxf4 {++}
1 0.000 +3.253 11 Qxf4
1 0.000 +3.253 97 Qxf4
2 0.000 +3.199 173 Qxf4 Kg8
2 0.000 +3.653 281 Qxf7+ {++} Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+
Bf6 5. Rh7+ Kf8 6. Rxc7
2 0.000 +7.311 560 Qxf7+ Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rh7+ Kg8 6. Rxc7 Bxg5
2 0.000 +7.311 739 Qxf7+ Kxf7 2. Rxh7+ Kf8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rh7+ Kg8 6. Rxc7 Bxg5
3 0.000 +7.711 1247 Qxf7+ {++} Kxf7 2. Rxh7+ Kf8 3. Rxf4+ Bf6 4. Rxc7
3 0.000 +8.537 1909 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+ Bf6
5. Rxc7
3 0.000 +8.537 2355 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+ Bf6
5. Rxc7
4 0.010 +8.937 2467 Qxf7+ {++} Kxf7 2. Rxh7+ Kg8 3. Rg7+ Kf8 4. Rxf4+
Bf6 5. Rxc7 Re8 6. Bxe8
4 0.010 +Mate07 5706 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
4 0.010 +Mate07 6212 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
5 0.010 +Mate07 9376 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
5 0.020 +Mate07 13380 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8#
6 0.030 +Mate07 26262 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
6 0.030 +Mate07 37390 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
7 0.060 +Mate07 67247 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
7 0.081 +Mate07 104025 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
8 0.111 +Mate07 155504 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
8 0.141 +Mate07 208117 Qxf7+ Kxf7 2. Rxh7+ Kg8 3. Rh8+ Kf7 4. Rxf4+ Bf6
5. Rxf6+ Ke7 6. Rh7+ Kd8 7. Rf8# {ht}
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