Author: leonid
Date: 15:06:54 04/17/01
Go up one level in this thread
On April 17, 2001 at 13:57:35, Heiner Marxen wrote:
>On April 17, 2001 at 13:12:22, leonid wrote:
>
>>On April 17, 2001 at 11:13:02, Heiner Marxen wrote:
>>
>>>On April 17, 2001 at 07:43:30, leonid wrote:
>>>
>>>>Hello!
>>>>
>>>>If you like to solve very "regular" mate position, then you have one.
>>>>
>>>>[D]R7/4P1Pq/1rR5/2pb1rnk/1Q3B2/4Nn2/1PB2Np1/2K1b1Q1 w - -
>>>>
>>>>Please, indicate your result.
>>>>
>>>>Thanks,
>>>>Leonid.
>>>
>>>According to Chest there are two key moves for mate in 7 moves:
>>>
>>>Qxg2 Bd2+ Qxd2 Bxc6 g8=Q Qxg8 Rxg8 Bd5 e8=Q+ Bf7 Nxf5 Nd4 Rxg5#
>>>Rh8 Bd2+ Qxd2 Be4 e8=Q+ Rf7 Qxf7+ Nxf7 Qd5+ Bf5 Rxh7+ Nh6 Rhxh6#
>>>
>>>(K7/600, 350MB hash, 9.3 minutes)
>>>
>>>Heiner
>>
>>Thanks, Heiner! My program demonstrate the worst possible branching factor for
>>this position. Even for seeing the 6 moves by brute force it took already 38 min
>>(Celeron 600. No hash). Only after your indication I went to see 7 moves by
>>brute force. It took for mine hefly 1 hours 5 min. And this is after my last
>>improvement that cut 6 moves brute force search already by 48%.
>>
>>Previously this position my solved by selective search in 10 moves.
>>
>>Leonid.
>
>Hi Leonid,
>
>From depth=6 in 38 minutes to depth=7 in 1h5min is a factor of less than 2.
>Even with the 48% improvement, the factor is just 4. That is quite
>different from Chest's timing (see below), and is unexpectedly low (for me).
This is not how I see branching factor. At depth 7 mate already found, so I
don't see that much correspondence between 6 and 7 moves. Bad branching factor I
looked this way:
4 moves - 1.86 sec
branching factor = 37
5 moves - 1 min 9 sec.
branching factor = 33.1
6 moves - 38 min 6 sec.
-------------------
7 moves - 1 hour 5 min 6 sec.
After writing this message, I went to see what was the time of solution for my
previous version. I waited for 3 hours (7 moves brute froce) and just
disconnected. Had no more patience to wait.
I went also to see the branching factor on Genius 2. Had only time for 4 moves
and 5.
4 moves - 7 sec.
branching factor 37
5 moves 4 min 25 sec.
Felt me in good company when I found that Genius have exactly the same branching
factor for four an five moves. Did not went to see his time for 6 moves. If he
will mimic my branching factor for 5 and 6, then it will be too long for me to
wait.
>My program shows a branching factor significantly larger than usual, but
>not "worst possible". Here is the timing info for increasing depths:
>
>depth seconds speed hash in hash out
># 1 0.00 0.87 1- 0
># 2 0.01 1.00 1- 0
># 3 0.03 0.97 83- 0
># 4 0.26 1.06 907- 0
># 5 2.59 1.30 13215- 0
># 6 31.77 1.58 184695- 0
># 7 559.19 1.81 3425552- 2347
>
>559.19 / 31.77 = 17.60 which is much smaller than 79 (initial legal moves).
>
>Here is statistics over remaining depth:
>
> moves quotient
>depth attacker defender att def
>mvx 7: 79 192 [ 79.000 2.430] mvskip lvskip
>mvx 6: 1167 1863 [ 6.078 1.596] 5
>mvx 5: 22875 25690 [ 12.279 1.123] 679
>mvx 4: 299329 334138 [ 11.652 1.116] 7313 4
>mvx 3: 3752287 3769416 [ 11.230 1.005]
>mvx 2: 22524391 7352320 [ 5.976 0.326]
>mvx 1: 2394158 0 [ 0.326 ]
>
>The "refutation table" shows which defender moves were chosen top level.
>Selecting the "right" defender moves is important for small search trees:
>
>refu 1: e8=Q+ Bf7 [ 6-]
>solu 4: Nf7 [ 5+]
>solu 5: Kh4 [ 1+]
>refu 2: e8=B+ Bf7 [ 6-]
>solu 6: Nf7 [ 5+]
>solu 7: Kh4 [ 1+]
>refu 3: Rh6+ Qxh6 [ 6-]
>refu 4: Qh1+ gxh1=Q [ 6-]
>refu 5: Qh2+ Nxh2 [ 6-]
>refu 6: g8=Q Bd2+ [ 6-]
>refu 7: g8=N Bd2+ [ 6-]
>refu 8: g8=R Bd2+ [ 6-]
>refu 9: g8=B Bd2+ [ 6-]
>refu 10: e8=N Bd2+ [ 6-]
>refu 11: e8=R Bd2+ [ 6-]
>refu 12: b3 Bd2+ [ 6-]
>refu 13: Nd3 Bd2+ [ 6-]
>refu 14: Nfd1 Bd2+ [ 6-]
>refu 15: Ne4 Bd2+ [ 6-]
>refu 16: Nfg4 Bd2+ [ 6-]
>refu 17: Nh3 Bd2+ [ 6-]
>refu 18: Nh1 Bd2+ [ 6-]
>refu 19: Nc4 Bd2+ [ 6-]
>refu 20: Nxd5 Bd2+ [ 6-]
>refu 21: Ned1 Bd2+ [ 6-]
>refu 22: Nxf5 Bxf2 [ 6-]
>solu 9: Bd2+ [ 6+]
>solu 10: Nxg1 [ 3+]
>solu 11: Nd2 [ 2+]
>solu 12: Nd4 [ 2+]
>solu 13: Ne5 [ 2+]
>solu 14: Qxf5 [ 5+]
>solu 15: Ra6 [ 3+]
>solu 16: Qxg7 [ 3+]
>solu 17: cxb4 [ 5+]
>solu 18: Rxb4 [ 5+]
>solu 19: Bxb4 [ 5+]
>solu 20: Rxc6 [ 6+]
>solu 21: Bxc6 [ 6+]
>refu 23: Nf1 Bd2+ [ 6-]
>refu 24: Neg4 Bd2+ [ 6-]
>refu 25: Nxg2 Bd2+ [ 6-]
>refu 26: Bxg5 Rxb4 [ 6-]
>solu 22: Bd2+ [ 6+]
>solu 23: Nxg1 [ 1+]
>solu 24: Ne5 [ 1+]
>solu 25: Nd2 [ 1+]
>solu 26: Nd4 [ 3+]
>solu 27: Qxg7 [ 1+]
>solu 28: Ra6 [ 1+]
>solu 29: cxb4 [ 6+]
>refu 27: Bg3 Bd2+ [ 6-]
>refu 28: Bh2 Bd2+ [ 6-]
>refu 29: Be5 Bd2+ [ 6-]
>refu 30: Bd6 Bd2+ [ 6-]
>refu 31: Bc7 Bd2+ [ 6-]
>refu 32: Bb8 Bd2+ [ 6-]
>refu 33: Bd3 Bd2+ [ 6-]
>refu 34: Be4 Bd2+ [ 6-]
>refu 35: Bxf5 Rxc6 [ 6-]
>solu 30: Bd2+ [ 6+]
>solu 31: Nxg1 [ 4+]
>solu 32: Nd4 [ 2+]
>solu 33: Nd2 [ 2+]
>solu 34: Ne5 [ 2+]
>solu 35: Rxb4 [ 2+]
>solu 36: Qxf5 [ 5+]
>solu 37: Qxg7 [ 2+]
>solu 38: Ra6 [ 2+]
>solu 39: cxb4 [ 2+]
>solu 40: Bxb4 [ 2+]
>refu 36: Bb1 Bd2+ [ 6-]
>refu 37: Bd1 Bd2+ [ 6-]
>refu 38: Bb3 Bd2+ [ 6-]
>refu 39: Ba4 Bd2+ [ 6-]
>refu 40: Rd6 Bd2+ [ 6-]
>refu 41: Re6 Bd2+ [ 6-]
>refu 42: Rf6 Bd2+ [ 6-]
>refu 43: Rg6 Bd2+ [ 6-]
>refu 44: Rxb6 Bd2+ [ 6-]
>refu 45: Rc7 Bd2+ [ 6-]
>refu 46: Rcc8 Bd2+ [ 6-]
>refu 47: Rxc5 Bd2+ [ 6-]
>refu 48: Rb8 Bd2+ [ 6-]
>refu 49: Rac8 Bd2+ [ 6-]
>refu 50: Rd8 Bd2+ [ 6-]
>refu 51: Re8 Bd2+ [ 6-]
>refu 52: Rf8 Bd2+ [ 6-]
>refu 53: Rg8 Bd2+ [ 6-]
>refu 54: Rh8 Bd2+ [ 5-]
>solu 41: Bd2+ [ 6+]
>solu 42: Nxg1 [ 5+]
>solu 43: Nd2 [ 2+]
>solu 44: Nd4 [ 2+]
>solu 45: Ne5 [ 2+]
>solu 46: Ra6 [ 4+]
>solu 47: cxb4 [ 4+]
>solu 48: Rxb4 [ 2+]
>solu 49: Bxb4 [ 4+]
>solu 50: Rxc6 [ 6+]
>solu 51: Bxc6 [ 6+]
>solu 52: Qxh8 [ 2+]
>solu 53: Rxf4 [ 4+]
>solu 54: Bxf2 [ 5+]
>solu 55: c4 [ 4+]
>solu 56: Ba2 [ 4+]
>solu 57: Rb7 [ 2+]
>solu 58: Bb3 [ 4+]
>solu 59: Be4 [ 5+]
>solu 60: Nf7 [ 2+]
>solu 61: Nh4 [ 5+]
>solu 62: Bf7 [ 4+]
>solu 63: Rf7 [ 2+]
>solu 64: Kh4 [ 2+]
>solu 65: Rb8 [ 2+]
>solu 66: Rb5 [ 2+]
>solu 67: Ne6 [ 2+]
>solu 68: Ne4 [ 1+]
>solu 69: Nh3 [ 1+]
>solu 70: Nh2 [ 2+]
>solu 71: Bc3 [ 4+]
>solu 72: Be6 [ 5+]
>solu 73: Bg8 [ 5+]
>solu 74: Bc4 [ 4+]
>solu 75: Re5 [ 2+]
>solu 76: Rf6 [ 5+]
>solu 77: Rf8 [ 2+]
>solu 78: Qh6 [ 1+]
>refu 55: Ra7 Bd2+ [ 6-]
>refu 56: Ra6 Bd2+ [ 6-]
>refu 57: Ra5 Bd2+ [ 6-]
>refu 58: Ra4 Bd2+ [ 6-]
>refu 59: Ra3 Bd2+ [ 6-]
>refu 60: Ra2 Bd2+ [ 6-]
>refu 61: Ra1 Bd2+ [ 6-]
>refu 62: Qf1 Bd2+ [ 6-]
>refu 63: Qgxe1 g1=Q [ 6-]
>refu 64: Qxg2 Bd2+ [ 5-]
>solu 79: Bd2+ [ 6+]
>solu 80: Ng1 [ 1+]
>solu 81: Nd2 [ 1+]
>solu 82: Nd4 [ 1+]
>solu 83: Ne5 [ 2+]
>solu 84: Qxg7 [ 1+]
>solu 85: Ra6 [ 1+]
>solu 86: cxb4 [ 1+]
>solu 87: Rxb4 [ 1+]
>solu 88: Bxb4 [ 1+]
>solu 89: Rxc6 [ 6+]
>solu 90: Bxc6 [ 6+]
>solu 91: Rxf4 [ 2+]
>solu 92: Bxf2 [ 1+]
>solu 93: c4 [ 1+]
>solu 94: Rb7 [ 1+]
>solu 95: Bb3 [ 1+]
>solu 96: Ba2 [ 1+]
>solu 97: Be4 [ 1+]
>solu 98: Nf7 [ 1+]
>solu 99: Nh4 [ 1+]
>solu 100: Bf7 [ 1+]
>solu 101: Rf7 [ 1+]
>solu 102: Kh4 [ 1+]
>solu 103: Rb8 [ 1+]
>solu 104: Rb5 [ 1+]
>solu 105: Ne6 [ 1+]
>solu 106: Ne4 [ 1+]
>solu 107: Nh3 [ 1+]
>solu 108: Nh2 [ 2+]
>solu 109: Bc3 [ 1+]
>solu 110: Be6 [ 5+]
>solu 111: Bg8 [ 1+]
>solu 112: Bc4 [ 1+]
>solu 113: Re5 [ 1+]
>solu 114: Rf6 [ 4+]
>solu 115: Rf8 [ 1+]
>solu 116: Qh6 [ 1+]
>solu 117: Qg6 [ 3+]
>solu 118: Qh8 [ 1+]
>solu 119: Qg8 [ 1+]
>refu 65: Qc4 Bd2+ [ 6-]
>refu 66: Qd4 Bd2+ [ 6-]
>refu 67: Qe4 Bd2+ [ 6-]
>refu 68: Qa4 Bd2+ [ 6-]
>refu 69: Qb5 Bd2+ [ 6-]
>refu 70: Qxb6 Bd2+ [ 6-]
>refu 71: Qb3 Bd2+ [ 6-]
>refu 72: Qxc5 Bd2+ [ 6-]
>refu 73: Qa3 Bd2+ [ 6-]
>refu 74: Qc3 Nxg1 [ 6-]
>refu 75: Qd2 Bxd2+ [ 6-]
>refu 76: Qbxe1 Rxc6 [ 6-]
>solu 1: Nd4 [ 2+]
>solu 2: Nd2 [ 2+]
>solu 3: Nxe1 [ 2+]
>solu 120: Nxg1 [ 6+]
>solu 121: Ne5 [ 2+]
>solu 122: Qxg7 [ 6+]
>solu 123: Ra6 [ 6+]
>refu 77: Qa5 Bd2+ [ 6-]
>refu 78: Kd1 Bb3 [ 6-]
>solu 8: Ne4 [ 5+]
>refu 79: Kb1 Nd2+ [ 6-]
>
>Have a nice day!
The same for you, Heiner!
Leonid.
>Heiner
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