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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