Author: Tim Foden
Date: 05:49:25 02/19/04
Go up one level in this thread
On February 19, 2004 at 08:19:30, Dieter Buerssner wrote:
>On February 19, 2004 at 03:03:53, Tim Foden wrote:
>
>>On February 18, 2004 at 10:15:28, Mihaly Szalai wrote:
>>
>>>[D]1knB4/8/7p/5R2/7K/8/3r4/7B w - - 0 1
>>>
>>>White has a very nice play here:
>>>1. Rb5+ Nb6 2. Bxb6! Rh2+ 3. Kg4! Rxh1 4. Bg1+! Kc7 5. Rb1! Kd7 6. Re1 Kc6 7.
>>>Rd1
>>>Kb5 8. Rc1 Ka4 9. Rb1 +-
>>>
>>>I wonder how many engines can see this line and how fast.
>>
>>The version of Green Light that I ended up with in Graz likes Rb5+ after 28
>>seconds.
>>
>> 15 27.640 +3.205 31454k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
>> Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
>> Ka4 10. Kf4
>>
>>It gets it after 1 minute 20 seconds. It's not quite the same line as above as
>>it does h5+ earlier than required (this is a transposition though), but
>>otherwise looks good:
>>
>> 17 1:19.85 +4.657 91517k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
>> Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
>> Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1
>>
>>I'll have to figure out what allows it to see this when my other versions of
>>Green Light that are in development do not :)
>
>Very impressive! For Yace null move makes a big difference in this pos.
I guess that's because there are a load of moves in a row for B that are
zugzwang.
>If I
>analyse the position 5 moves into the line, with null move disabled, it sees
>that black is lost about 6 depths earlier than with null move enabled. Perhaps
>you changed something about null move?
Yes, the Graz version has some extra code to switch of null move and it kicks in
in this position. My other versions do not, so they have trouble seeing it at
all.
>Or about scoring, when the rook is in the
>corner with practically no mobility (which, when penalized enough could avoid
>misleading null move fail highs).
>
>BTW. Don't you give KRBKR(+Ps) a drawish score in GLC?
Not quite. I score KRB-KR as drawish. But the pawns cause this to be switched
off. It's something I planned to look at when time permits, but this position
prompted me to hava a go this morning. Now it should score KRB-KR as about
+0.7, KRB-KRP as about +0.4, KRB-KRPP as about -0.5, and KRB-KRPPP as about
-1.4.
Now, instead of considering Bd5 for ages it only considers Rb5+, and now with
only a +1.0 score rather than a +3.1 one. It still takes quite 17 plies to see
the correct PV though (but in much less time)...
17 37.344 +4.525 48271k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1
Cheers, Tim.
Full analysis: GLC 3.01.1.2, 96MB Hash, AXP 2.1GHz:
Game stage: Endgame
Current eval: 0.391
Ply Time Score Nodes Principal variation
5 0.000 +1.086 7623 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 {ht} 4. Rxh6
5 0.020 +1.086 10654 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 {ht} 4. Rxh6
6 0.030 +1.045 18393 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 4. Bf5+ Kc7 5.
Rxh6
6 0.030 +1.045 27939 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 4. Bf5+ Kc7 5.
Rxh6
Generating internal KP-K end-game table...
Done (0.141 secs)
7 0.191 +1.072 41713 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 4. Rxh6 Rd4 5.
Re6
7 0.211 +1.072 66782 Rb5+ Nb6 2. Be4 Rxd8 3. Rxb6+ Kc8 4. Rxh6 Rd4 5.
Re6
8 0.271 +0.999 144012 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rxh6 Rd6 5.
Rh7+ Rd7 6. Rh6
8 0.321 +0.999 217549 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rxh6 Rd6 5.
Rh7+ Rd7 6. Rh6
9 0.401 +1.012 321927 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kb8 5.
Rxh6 Rd4 6. Bc6 Kc8
9 0.521 +1.012 474637 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kb8 5.
Rxh6 Rd4 6. Bc6 Kc8
10 0.741 +1.017 741075 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Rg8+ 6. Kf4 Rf8+ 7. Ke5 Re8+ 8. Kd4 Re2
10 0.892 +1.017 943248 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Rg8+ 6. Kf4 Rf8+ 7. Ke5 Re8+ 8. Kd4 Re2
11 1.252 +1.059 1389323 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Rc8 6. Be4 Rc4 7. Kf4 Rc3
11 1.422 +1.059 1637367 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Rc8 6. Be4 Rc4 7. Kf4 Rc3
12 2.434 +1.036 2928058 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Be4 Rd6 7. Rh7+ Ke6 8. Kf4 Rd4
12 2.884 +1.036 3579537 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Be4 Rd6 7. Rh7+ Ke6 8. Kf4 Rd4
13 3.786 +1.086 4737994 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Be4 Rd6 7. Rh7+ Ke6 8. Kf4 Rd4 9.
Rh6+ Ke7
13 4.427 +1.086 5658893 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Be4 Rd6 7. Rh7+ Ke6 8. Kf4 Rd4 9.
Rh6+ Ke7
14 6.279 +1.088 8012396 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Rd4+ 9.
Ke3 Rc4 10. Be4
14 7.541 +1.088 9794245 Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Rd4+ 9.
Ke3 Rc4 10. Be4
15 11.056 +1.088 14283k Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Rd4+ 9.
Be4 Rd6 10. Rc7 Ke6
15 15.182 +1.088 19405k Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Rd4+ 9.
Be4 Rd6 10. Rc7 Ke6
16 22.923 +1.101 29003k Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Ke6 9.
Be4 Rd2 10. Bf5+ Kf6 11. Be4
16 28.391 +1.101 35948k Rb5+ Nb6 2. Kg3 Rxd8 3. Rxb6+ Kc7 4. Rc6+ Kd7 5.
Rxh6 Ke7 6. Kf4 Rd6 7. Rh7+ Kf6 8. Bc6 Ke6 9.
Be4 Rd2 10. Bf5+ Kf6 11. Be4
17 32.958 +1.501 41564k Rb5+ {++} Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8
5. Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9.
Rc1 Ka4 10. Rb1 Ka3 11. Bc5+ Ka2 12. Rxh1
17 37.344 +4.525 48271k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1
17 45.966 +4.525 61805k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1
18 56.381 +4.425 78384k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1 Kb4
18 1:13.59 +4.425 106095k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1 Kb4
19 1:14.32 +4.825 107078k Rb5+ {++} Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8
5. Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9.
Rc1 Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1 h3+
13. Kxh3 Kb4
19 1:28.96 +4.832 129169k Rb5+ Nb6 2. Bxb6 Rh2+ 3. Kg4 Rxh1 4. Bg1+ Kc8 5.
Rb1 Kd7 6. Re1 h5+ 7. Kg3 Kc6 8. Rd1 Kb5 9. Rc1
Ka4 10. Rb1 h4+ 11. Kg2 Rxg1+ 12. Rxg1 Kb4 13.
Kh3
Analyse>exit
local: t=1:41.77 nps=1457922.1 n=148368355 (36.1% / 63.9%)
total: t=1:41.77 nps=1457922.1 n=148368355
stats: fh=94.2%/2.61%/0.845% draws=213412
trans: probes=53286158 hits=14685947 (27.56%) draft=9929111 (18.63%)
tcuts: exact=2913 (0.01%) upper=5123726 (9.62%) lower=3680081 (6.91%)
tstor: exact=1652 (0.01%) upper=8631169 (61.29%) lower=5449560 (38.70%)
ext: check=7924229 recap=183966 ppush=723 1rep=116834 thrt=123552
q-moves: gen=20128458 tested=16570151 made/un=5000029 max-dep=5
max eval diff: part-1=4.140 part-2=1.559
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Last modified: Thu, 15 Apr 21 08:11:13 -0700
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