Rybka vindicates Fischer!

[AdminX]

The position below is from Fritz 6 versus Steve Ham after whites 56th move:
http://www.correspondencechess.com/camp ... _hambl.htm

[d]8/2k5/1pR5/1K6/P2b4/8/8/8 b - - 0 0

Notes from Steve Ham

"Now dear reader, you are entitled to some much needed humor. As you see from my previous commentary, I've written that the position is drawn and many strong masters agreed with me. In fact, several OTB and Correspondence Masters heaped sympathy upon me for the following dilemma. How do I explain to weaker players that the position is a draw and that White can't make progress, in spite of the chess engine's evaluation of a win? I don't want to spend the rest of my life playing this endgame out with Fritz 6a while it exhausts every possible move until it agrees the position is a draw. So the other masters advised me to play just a few more moves until it is evident that the chess engine has no plan other than forcingmy King or Bishop to move. Then we all agreed that everyone would be satisfied that Fritz was given every chance to prove itself, but failed.So do you, dear reader, see that the position is drawn? Do you understand that if the pawns are exchanged that Black has a book draw by putting his King on a8? Do you see that Black's King and Bishop hold the b-pawn so White can make no headway? If you agree with me about this, then we are totallyWRONG! At least that's what Bobby Fischer says.

Simon Finn wrote that a nearly identical position arose with colors reversed in Reshevsky-Fischer, 11th match game, Los Angeles 1961. This is covered in Fischer's My 60 Memorable Games, as game 28 (see notes to Black's 53rd) and note that the colors are reversed. Both grandmasters agreed to a draw, but Fischer later claimed he found an endgame study-like win for the side with the Rook! Simon Finn, after reviewing Fischer's notes saw that there are 5 steps that must be followed in order to win.

Step 1: White moves his King to a6 and his Rook to b5.

Step 2: Now that the Rook on b5 blocks Black from playing b5+ with a discovered check, White advances his King to a8. Black should keep his King near c7 or c8 to prevent White's King from moving to b8 or b7.

Step 3: White transfers his Rook to the c-file.

Step 4: White advances his pawn to a7, using the Rook to pin Black's Bishop to his King.

Step 5: White exchanges his Rook for Black's Bishop. This draws Black's King to c6 and thus enables White to move his King off the b-file and promote his pawn.


This all sounded far too theoretical the first few times I read it through. But, even those of you who hate endgame studies will surely enjoy this one. Let's move through this process of discovery together with the analysis I did late at night.

Step 1: 56 Ka6!, Be3 57 Rg3, Bd4 58 Rb3, Kc6 59 Rb5, Bc5 (59Kc7 60 Ka7, Kc6 61 Kb8 transposes, as does 60Bc5 61 a5).
Now step 2: 60 Ka7, Bd4 (60Kc7 61 a5, Kc6 62 Rb6+ wins) 61 Kb8, Be3.
Next is step 3: 62 Rb2, Bc5 63 Rc2, Kd6 (63b5!? 64 a5, b5 65 a6??, b3 66 a7, bxc2 67 a8/Q+, Kb5 68 Qa1, Kc4 69 Kc7, Be3 may draw since the Bishop is the same color as the queening square. But White wins quickly with 65 Rb2!, Kb5 11 Kb7 since mating threats abound.).
And now we don't even need steps 4-5 because 64 Kb7, Be3 65 Rc6+, Kd7 66 Rc3, Bg1 (66Bc5 12 a5 wins, as in Step 4) 67 Rd3+, Ke6 68 Kc6, Bf2 69 Rb3, Bd4 70 Rxb6 wins. Amazing! So now dear reader, are you prepared to jump on board Bobby Fischer's bandwagon and claim that White has a win here? Then I say you are totallyWRONG AGAIN!

With all due respect to Bobby Fischer and his claims to have no errors in his published analysis, there is an error in his published analysis. We can transpose directly into his analysis from My 60 Memorable Games but with colors reversed via 58Bc5 59 Rb5, Bf2. We are now following his line which runs 60 Ka7, Bd4 61 Ka8 (remember the steps above), Kc6 62 Rb1, Bc5 63 Rc1, Kc7 (63Kd6?? 64 Kb7 wins) 64 a5, Kc6 65 a6, Kc7 66 a7, Kc8 67 Rh1, Kc7 68 Rh7+, Kc8 69 Rh6!, Kc7 70 Rc6+!!, Kxc6 71 Kb8, Bd6+ 72 Kc8 "and the pawn queens". This is really beautiful indeed. But instead 67Bd6!! 68 Rh6, Be5 69 Rxb6, Kc7 70 Re6, Bf4 71 Re2, Bd6 72 Rc2+, Kb6 draws because Black traps White's King on a8. How about that for a little endgame magic? Now that the drawing scheme has now been revealed, Helmut Froeyman of Belgium subsequently demonstrated a simpler way to draw with 63b5 64 a4, b4 65 a6, Kb6 66 Rxc5 (66 a7, Bd6 draws), Kxc5 67 a7, b3 68 Kb7, b2 69 a8/Q, b1/Q+, which draws.

So, now that we've made history by busting Fischer's printed analysis and dug deeply into this position, we can safely conclude that this entire line is a safe draw for Black. If we accept that, then we areyou guessed it, TOTALLY WRONG!

Dan Andersson of Sweden and Helmut Froeyman of Belgium both subsequently showed that White's winning process begins with 63 Kb8!, instead of 63 Rc1. Now, please follow along for some head-spinning endgame magic. After 63 Kb8!, Bd4 64 Kc8! (this tempo loser forces Black into zugzwang, as will soon be evident), Bf2 65 Rc1+, Bc5 66 Kb8, b5 (allowing the White King to reach b7 is tantamount to resignation) 67 a5, b4 68 a6, b3 (68Kb5 69 Rxc5 wins) 69 a7 wins. If Black instead tries to prevent White's Rc1+ with 64Be3, then 65 Rb2, Bd4 66 Rc2+, Bc5 67 Rc1 transposes to the winning line already given.

Now I hear you cry out that since this winning mechanism is known, Black should then play 62Kc7, instead of 62Bc5, in order to transpose back into my Fischer busting drawing line. For example 62Bc5 63 Rc1+, Bc5 64 a5, Kc6 reaches the drawing line I gave earlier. So in conclusion, Black finally reaches the safe haven afforded by the drawn position, right? WRONG AGAIN! Helmut Froeyman discovered the brilliant 64 Ka7!!, Kc6 (64, Kc8 65 a5 wins) 65 Kb8 which transposes back into his bust of my bust of Fischer's line. Given this knowledge, that means White also can win with 62 Kb8 in addition to 62 Rb1. Can we thus conclude that this endgame's magical mystery tour been totally solved? I think so!"

Now on to my notes (Ted Summers), As I was playing over this game, which I must say was a joy to read because of the great annotation, I reached the position posted above. Given that the hardware used at the time was a Pentium III 500 Mhz with 256MB ram that the game was played on, I decided to take a closer look at the position with the help of todays Hardware (Q6700) and Rybka 3.

[d]8/2k5/1pR5/1K6/P2b4/8/8/8 b - - 0 0

Analysis by Deep Rybka 3 64-bit:

1...Kb7 2.Rd6 Be3 3.Rd7+ Kc8 4.Kc6
+- (3.04) Depth: 6 00:00:00 2kN
+- (3.11) Depth: 7 00:00:00 2kN

1...Kd7
+- (2.84 !) Depth: 7 00:00:00 3kN

1...Kb7 2.Rd6 Be3 3.Rd7+ Kc8 4.Kc6
+- (3.11) Depth: 7 00:00:00 3kN
+- (3.12) Depth: 8 00:00:00 3kN

1...Kd7 2.Rc1 Be3 3.Re1 Bf2[] 4.Rf1
+- (2.91 !) Depth: 8 00:00:00 4kN
+- (3.19) Depth: 22 00:00:01 228kN, tb=1648

1...Kb7 2.Rd6 Bf2 3.Rd7+ Kb8 4.Ka6[] Bc5 5.Rf7 Be3 6.Rf5[]
+- (3.19) Depth: 23 00:00:03 517kN, tb=4500
+- (4.49) Depth: 42 00:35:38 458mN, tb=4708845

1. ... Kb7
2. Rd6 Bf2
3. Rd7 Kb8
4. Ka6 Bc5


[d]1k6/3R4/Kp6/2b5/P7/8/8/8 w - - 0 1

Analysis by Deep Rybka 3 64-bit:

5.Rd1
+- (5.09) Depth: 25 00:00:00 0kN
+- (5.12) Depth: 35 00:01:56 33881kN, tb=87124


5. Rd1 Bf2
6. Rb1 Kc7
7. Rb5 Bd4
8. Ka7 Kc6
9. Kb8 Bf2
10. Rb2


[d]1K6/8/1pk5/8/P7/8/1R3b2/8 b - - 0 1

Analysis by Rybka 3:

10...Bc5 11.Kc8
+- (5.09) Depth: 22 00:00:00 0kN
+- (5.44) Depth: 25 00:01:34 21557kN, tb=63582

10...Be3 11.Rb1
+- (5.12) Depth: 25 00:02:57 40881kN, tb=122093
+- (5.12) Depth: 28 00:03:17 47091kN, tb=136346

10. ... Be3


[d]1K6/8/1pk5/8/P7/4b3/1R6/8 w - - 0 1

Analysis by Deep Rybka 3 64-bit:

11.Kc8 Bc5 12.Rb1
+- (5.09) Depth: 6 00:00:00 0kN, tb=8
+- (5.09) Depth: 19 00:00:00 1kN, tb=23

11.Rb1
+- (5.11) Depth: 19 00:00:00 5kN, tb=23
+- (5.09) Depth: 20 00:00:00 13kN, tb=24

11.Rc2+
+- (5.27) Depth: 20 00:00:16 5868kN, tb=5833
+- (8.49) Depth: 22 00:04:08 124mN, tb=45134

11. Rc2


[d]1K6/8/1pk5/8/P7/4b3/2R5/8 b - - 0 1

Analysis by Deep Rybka 3 64-bit:

11...Bc5 12.Rc1
+- (5.09) Depth: 6 00:00:00 0kN
+- (5.59) Depth: 19 00:00:05 1832kN, tb=2207

11...Kd5 12.Kb7
+- (5.12) Depth: 19 00:00:06 2061kN, tb=3153
+- (6.36) Depth: 20 00:00:37 19686kN, tb=4227

11...Bc5 12.Rc1
+- (5.58) Depth: 20 00:00:41 20626kN, tb=7708
+- (10.66) Depth: 22 00:02:26 60566kN, tb=40298

11. ... Bc5
12. Rc1


[d]1K6/8/1pk5/2b5/P7/8/8/2R5 b - - 0 1

Analysis by Deep Rybka 3 64-bit:

12...Kd7 13.Kb7
+- (5.09) Depth: 6 00:00:00 0kN
+- (5.12) Depth: 15 00:00:00 61kN, tb=2

12...Kd6 13.Kb7
+- (5.09) Depth: 15 00:00:00 61kN, tb=2
+- (#23) Depth: 18 00:00:01 531kN, tb=954

12...Kd7 13.Kb7
+- (5.59) Depth: 18 00:00:01 700kN, tb=1612
+- (#24) Depth: 22 00:03:30 82485kN, tb=49077

Here is the complete PGN of the game:

[Event "Computer CC Challenge Match"]
[Site "?"]
[Date "1999.12.03"]
[Round "?"]
[White "Fritz 6"]
[Black "Ham, Steve"]
[Result "1/2-1/2"]
[PlyCount "146"]

1. e4 c5 2. Nf3 d6 3. Bb5+ Bd7 4. Bxd7+ Qxd7 5. c4 Nc6 6. Nc3 g6 7. d4 cxd4 8.
Nxd4 Nf6 9. O-O Bg7 10. Nde2 Qe6 11. Nd5 Qxe4 12. Nc7+ Kd7 13. Nxa8 Qxc4 14.
Nb6+ axb6 15. Nc3 b5 16. Bg5 Ne4 17. Nxe4 Qxe4 18. a4 b4 19. Re1 Qf5 20. Qd2
Ra8 21. Be3 Ke8 22. h3 Ra5 23. Bb6 Rd5 24. Qe2 Qd3 25. Qg4 e6 26. Rad1 Qb3 27.
Rxd5 Qxd5 28. Rd1 Qb3 29. Rxd6 Qxb2 30. Qd1 Qa1 31. Qxa1 Bxa1 32. Rd1 Bf6 33.
Kf1 h5 34. Ke2 Be7 35. Kd3 Ne5+ 36. Kc2 Nd7 37. Bd4 Nc5 38. Bxc5 Bxc5 39. f3
Ke7 40. g4 hxg4 41. hxg4 Bd6 42. Kb3 Kd7 43. Kc4 f5 44. g5 e5 45. Kd5 b6 46.
Rc1 Bc7 47. Rc4 e4 48. fxe4 fxe4 49. Rxb4 e3 50. Re4 Bd8 51. Rxe3 Bxg5 52. Re6
Kc7 53. Kc4 Bh4 54. Rxg6 Bf2 55. Kb5 Bd4 56. Rc6+ Kb7 57. Re6 Kb8 58. Rd6 Be3
59. Rd8+ Kb7 60. Rd7+ Kc8 61. Re7 Bd4 62. Kc6 Kb8 63. Kd5 Bc5 64. Rd7 Bf2 65.
Rf7 Bg1 66. Rd7 Bf2 67. Kc4 Kc8 68. Re7 Bc5 69. Re5 Kb7 70. Kb5 Bd4 71. Re7+
Kc8 72. Re8+ Kb7 73. Re7+ Kc8 1/2-1/2

[AdminX]

Felix over on the Rybka Forum, showed that the position is a mate in 36, thank to online 6 man tablebases in Aquarium which confirms my findings.

1... Kb7 2. Rh6 Be3 3. Rh7+ Kc8 4. Ka6 Bd4 5. Rh5 Be3
6. Rb5 Kc7 7. Ka7 Bc5 8. Ka8 Be3 9. Rb4 Bc5 10. Rb2 Kc6 11. Kb8 Bd6+ 12. Ka7
Bc5 13. Ka6 Bd4 14. Rc2+ Bc5 15. Rc3 Kd6 16. Kb7 Bf2 17. Rd3+ Ke7 18. Rd5 Bg1
19. Kc6 Bf2 20. Rb5 Kd8 21. Rb1 Bc5 22. a5 bxa5 23. Kxc5 Ke7 24. Rb5 a4 25. Ra5
a3 26. Kd5 a2 27. Rxa2 Kf6 28. Ra4 Kf7 29. Rf4+ Kg6 30. Ke6 Kg5 31. Re4 Kg6 32.
Re5 Kg7 33. Rg5+ Kh6 34. Kf6 Kh7 35. Rg4 Kh8 36. Kf7 Kh7 37. Rh4#

[Yar]

[d]8/2k5/1pR5/1K6/P2b4/8/8/8 b - - 0 0 this position is lost for black. 6 man Tbs says:
Kb7 - forced mate in 36
Kb8 - forced mate in 35
kd7 - forced mate in 24
kd8 - forced mate in 12.

With best regards,
Yar

[Stephen Ham]

Hi Ted,

Thanks for your interest in my games!

I'll give your analysis a look after the weekend, which will be spent on my daughter's 10th birthday.

All the very best.
Steve