Author: Robert Hyatt
Date: 11:25:17 10/01/01
Go up one level in this thread
On October 01, 2001 at 14:17:32, Eugene Nalimov wrote:
>On October 01, 2001 at 12:04:51, Robert Hyatt wrote:
>
>>On October 01, 2001 at 09:56:06, Mike Hood wrote:
>>
>>>Eugene, I think I understand your answer in part, but please help me further.
>>>I've quoted the whole file kbpk.tbs below, and I have three questions:
>>>
>>>1) There is a Mate in 31 listed, but no Mate in 30 or Mate in 29. Is this
>>>because the Mate in 31 involves an immediate transition into another tablebase,
>>>such as kpk.tbs? Maybe if you could tell me the exact position of this Mate in
>>>31 it would be obvious to me.
>>
>>Most likely it is a transposition into a KBN vs K endings. In a position
>>where promoting to a queen would be a stalemate.
>
>[D]/3P/KBk////// w
+---+---+---+---+---+---+---+---+
8 | | | | | | | | |
+---+---+---+---+---+---+---+---+
7 | | | | P | | | | |
+---+---+---+---+---+---+---+---+
6 | K | B | *K| | | | | |
+---+---+---+---+---+---+---+---+
5 | | | | | | | | |
+---+---+---+---+---+---+---+---+
4 | | | | | | | | |
+---+---+---+---+---+---+---+---+
3 | | | | | | | | |
+---+---+---+---+---+---+---+---+
2 | | | | | | | | |
+---+---+---+---+---+---+---+---+
1 | | | | | | | | |
+---+---+---+---+---+---+---+---+
a b c d e f g h
1. d8=N+ Kd6 2. Nb7+ Kd5 3. Nc5 Kc4 4. Ne4 Kd5 5. Ng3 Kc6 6. Be3
Kc7 7. Kb5 Kd6 8. Kb6 Kd5 9. Bh6 Kd4 10. Kc6 Ke5 11. Bg5 Kd4 12.
Bf4 Kc4 13. Be3 Kd3 14. Ba7 Kc4 15. Bc5 Kb3 16. Kb5 Kc3 17. Bb6 Kd3
18. Kb4 Kc2 19. Kc4 Kb1 20. Nf5 Kc1 21. Ba5 Kd1 22. Kd3 Kc1 23. Bc3
Kb1 24. Kc4 Kc1 25. Ne3 Kb1 26. Kb3 Kc1 27. Ba5 Kb1 28. Bd2 Ka1 29.
Nc4 Kb1 30. Na3+ Ka1 31. Bc3#
A good guess, eh? :)
>
>>>
>>>2) Why are no broken positions listed for btm? I presume that "wka1 wba6 wpa7
>>>bkb1" is at least one broken position for btm.
>>>
>>>3) All the numbers ought to be even, because every position containing one pawn
>>>can be mirrored left-right. Is the presence of odd numbers because your
>>>statistics are the number of positions in your already simplified/compressed
>>>chess board?
>
>Reported numbers are number of positions in file, i.e. after indexing removed
>loat of duplicate and illegal positions. Including illegal position you
>reported.
>
>Eugene
>
>>>Thanks,
>>>
>>>Mike
>>>
>>>kbpk.tbs
>>>========
>>>wtm: Draws: 174804
>>>wtm: Mate in 31: 1
>>>wtm: Mate in 28: 1
>>>wtm: Mate in 26: 11
>>>wtm: Mate in 25: 4
>>>wtm: Mate in 24: 25
>>>wtm: Mate in 23: 167
>>>wtm: Mate in 22: 476
>>>wtm: Mate in 21: 1917
>>>wtm: Mate in 20: 6110
>>>wtm: Mate in 19: 17489
>>>wtm: Mate in 18: 36103
>>>wtm: Mate in 17: 85135
>>>wtm: Mate in 16: 150419
>>>wtm: Mate in 15: 186502
>>>wtm: Mate in 14: 209994
>>>wtm: Mate in 13: 283840
>>>wtm: Mate in 12: 406655
>>>wtm: Mate in 11: 460888
>>>wtm: Mate in 10: 442601
>>>wtm: Mate in 9: 440135
>>>wtm: Mate in 8: 436186
>>>wtm: Mate in 7: 406369
>>>wtm: Mate in 6: 303115
>>>wtm: Mate in 5: 157067
>>>wtm: Mate in 4: 68023
>>>wtm: Mate in 3: 29622
>>>wtm: Mate in 2: 9838
>>>wtm: Mate in 1: 3118
>>>wtm: Broken positions: 500513
>>>btm: Lost in 0: 117
>>>btm: Lost in 1: 873
>>>btm: Lost in 2: 2793
>>>btm: Lost in 3: 8892
>>>btm: Lost in 4: 29591
>>>btm: Lost in 5: 84157
>>>btm: Lost in 6: 226693
>>>btm: Lost in 7: 415728
>>>btm: Lost in 8: 455096
>>>btm: Lost in 9: 447616
>>>btm: Lost in 10: 430805
>>>btm: Lost in 11: 422716
>>>btm: Lost in 12: 394004
>>>btm: Lost in 13: 338834
>>>btm: Lost in 14: 282260
>>>btm: Lost in 15: 243794
>>>btm: Lost in 16: 209974
>>>btm: Lost in 17: 137192
>>>btm: Lost in 18: 70856
>>>btm: Lost in 19: 33990
>>>btm: Lost in 20: 13627
>>>btm: Lost in 21: 7010
>>>btm: Lost in 22: 4168
>>>btm: Lost in 23: 2492
>>>btm: Lost in 24: 944
>>>btm: Lost in 25: 384
>>>btm: Lost in 26: 129
>>>btm: Lost in 27: 48
>>>btm: Lost in 28: 24
>>>btm: Lost in 31: 2
>>>btm: Draws: 859923
>>>
>>>
>>>
>>>On September 28, 2001 at 13:37:24, Eugene Nalimov wrote:
>>>
>>>>DTM, not DTC. After capture or promotion resulting position is stored in the
>>>>other TB, not in the current one.
>>>>
>>>>Eugene
>>>>
>>>>On September 28, 2001 at 12:38:55, Mike Hood wrote:
>>>>
>>>>>Thanks for the reply, Eugene. I'm willing to accept I may be wrong, but how do
>>>>>you explain the discrepancies I named?
>>>>>
>>>>>Mike
>>>>>
>>>>>On September 28, 2001 at 11:11:33, Eugene Nalimov wrote:
>>>>>
>>>>>>There is no bug in TBSTAT, and statistics is correct.
>>>>>>
>>>>>>Eugene
>>>>>>
>>>>>>On September 28, 2001 at 08:27:37, Mike Hood wrote:
>>>>>>
>>>>>>>On September 19, 2001 at 04:23:39, Les Fernandez wrote:
>>>>>>>
>>>>>>>>Has anyone tabulated the total win-lose-draw-broken positions for first the 3
>>>>>>>>then 4 and then the 5 piece sets? I know that the information is available on
>>>>>>>>Bobs ftp site but hoping that someone has already done it for both WTM and BTM
>>>>>>>>so I dont have to do them one by one.
>>>>>>>>
>>>>>>>>ie:
>>>>>>>>
>>>>>>>>EGTB WINS LOSE DRAW BROKEN
>>>>>>>>
>>>>>>>> 3
>>>>>>>> 4
>>>>>>>> 5
>>>>>>>
>>>>>>>This is theoretically possible, but not very sensible at the moment. Most of the
>>>>>>>TBS files on Robert Hyatt's ftp server are defective, probably due to a bug in
>>>>>>>TBSTAT.
>>>>>>>
>>>>>>>For instance:
>>>>>>>
>>>>>>>krrk.tbs -- On black's move there are 1032 positions that lose in 16, but on
>>>>>>>white's move the longest mate is Mate in 7.
>>>>>>>
>>>>>>>kqrkr.tbs -- On black's move there are 60 moves that are Mate in 5, but there
>>>>>>>are ZERO moves that are Mate in 4.
>>>>>>>
>>>>>>>kbpk.tbs -- On white's move there is 1 position that is Mate in 31, but there
>>>>>>>are ZERO moves that are Mate in 30.
>>>>>>>
>>>>>>>In most of the TBS files the number of broken positions is not listed.
>>>>>>>
>>>>>>>Over 50% of the TBS files are obviously defective, and I can't vouch for the
>>>>>>>validity of the others. And, to ask a naive question, shouldn't the number of
>>>>>>>Mates/Losses/Draws in a pawnless tablebase always be divisible by 4?
>>>>>>>
>>>>>>>I've reported the bug to Eugene by email a few weeks ago, but it hasn't been
>>>>>>>fixed yet.
>>>>>>>
>>>>>>>Mike
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