Difficult endgames

[peter]

If you have fritz GUI with playchess subscription then we can try.

Hi Jon!

As said in my last posting, I don't think pure eng-eng-games here to prove anything without doubt.

Even if you let play engines alone with corr.- TC, they won't see fortress coming neither avoid it, not to speak about build it up.

So Black is favored by the position as for pure material advantage speaking about eng-eng.
If I manage to hold draw interactively aginst SF with long TC on strong hardware, I'll post it again, if not, I'd say Black yet has decisive advantage maybe

[Nordlandia]

Peter: Is it possible to force the black king over to the queenside, If rook remains on e2.

If so what prospects will the BK do as b3 entrance is blocked by knight

Maybe d6 is best square for black king as it can go to both sides, if needed.

[d]8/5p2/3k4/3p2p1/1ppN2P1/2Pq1P2/1PR2K2/8 b - - 0 1

[peter]

[d]8/5p2/3k4/3p2p1/1ppN2P1/2Pq1P2/1PR2K2/8 b - - 0 1

That's one of the positions with rather high eval (SF 2.60) but no progress to be seen in output- lines.

How did you reach it, Jon?

[Nordlandia]

I think you found it couple of days ago.

http://www.talkchess.com/forum/viewtopi ... 91&t=63337

Of course b4 breakthrough is the only way to force disharmony in the white camp, combined with pawn advancements on the king side. Granting black king entrance, but as you pointed out, black king can't infiltrate on the king side.

My intuition dictates probably draw, still not 100% certain.

[Nordlandia]

Here is original pgn notation from endgame starting position.

Annotation is with "Fritz 15 Let's Check" analysis.

[pgn][Event "Dushanbe"]
[Site "Dushanbe"]
[Date "1980.??.??"]
[Round "?"]
[White "Goldin"]
[Black "Korzubov"]
[Result "0-1"]
[SetUp "1"]
[FEN "6k1/pp3p2/6p1/3p4/2pN4/P1P2P1P/1P1qR1P1/6K1 b - - 0 1"]
[PlyCount "131"]
[EventDate "1980.??.??"]
[SourceDate "2003.11.11"]

1... Qc1+ 2. Kf2 f5 3. Kg3 Qg5+ 4. Kh2 f4 5. Re8+ Kf7 6. Re2 a6 7. Ne6 Qh4 8.
Nd4 b5 9. Kg1 Qf6 10. Kh2 Qb6 11. Re5 Qb7 12. Kh1 Qd7 (12... a5 13. Re2 b4 {
-2.14/35 Stockfish 8 64}) 13. Kg1 a5 14. Kh2 Qd6 15. Re2 b4 16. axb4 axb4 (
16... axb4 17. Rc2 Qf6 {-1.56/30 Houdini 4 x64}) 17. Kh1 Qa6 18. Kh2 Qa1 19.
Rc2 Qe1 20. Re2 Qd1 21. Rf2 (21. Rc2 Qd3 22. Rc1 {-1.85/37 Stockfish 8}) 21...
Qa1 22. Rc2 Kf6 23. Nc6 Qd1 24. Nd4 Qd3 25. Rc1 Qe3 26. Rc2 Qe1 27. Re2 Qb1 28.
Rd2 Qa1 29. Rc2 Ke7 (29... g5 30. Nc6 Qd1 {-1.81/47 Stockfish 6 64}) 30. Re2+
Kd7 31. Rc2 Kc8 32. Ne6 Kb7 33. Nd4 Kb6 34. Ne6 Kb5 (34... Kc6 35. Nd4+ Kd6 {
-1.81/40 Stockfish 6 64}) 35. Nd4+ Ka4 36. g3 g5 37. g4 Qe1 38. Kg2 Qg3+ 39.
Kf1 Qxh3+ 40. Kf2 Qh2+ 41. Ke1 Qh1+ 42. Kf2 Qd1 43. Re2 Qd3 44. Rc2 Qxc2+ 45.
Nxc2 bxc3 46. bxc3 Kb3 47. Nb4 d4 48. cxd4 Kxb4 49. Ke2 c3 50. d5 Kb3 51. d6 c2
52. d7 c1=Q 53. d8=Q Qe3+ 54. Kd1 Qxf3+ 55. Kd2 Qe3+ 56. Kd1 Qe5 57. Kd2 (57.
Kd2 Qe3+ 58. Kd1 {-2.70/21 Fritz 13}) 57... Kc4 58. Qc8+ Qc5 59. Qa6+ Kd5 60.
Qb7+ Ke5 61. Qg7+ Ke4 62. Qh7+ Kf3 63. Qh3+ Kf2 64. Qh2+ Kf1 65. Qh5 Qd5+ 66.
Kc1 Kg2 0-1

[/pgn]

https://nb.lichess.org/P3yoPZGY

http://www.viewchess.com/cbreader/2017/ ... 10031.html

[peter]

My intuition dictates probably draw, still not 100% certain.

As for my personal pov, Jon, it's a fortress as long as I'm not shown anything new, but I can't prove it to be a forced draw neither

[peter]

as long as I'm not shown anything new

How easily Whtie can fail can be seen here again.

SF (as far as I remember at about depth 50) with full Syzygys played

[d]6k1/pp3p2/6p1/3p4/2pN4/P1P2P1P/1P1qR1P1/6K1 b - - 0 1

1... Qc1+ 2. Kf2 Kg7 3. Kg3 (?) Qg1 4. h4 (?)

and from that onwards Black's evals start rising on and on.

4...a6 5. Kg4 Qc1 6. Kg3 b5 7. Kg4 Kf6 8. Rf2
Qg1 9. Kg3 Qe1 10. Nc2 Qd1 11. Nd4 Kg7 12. Rc2 Qe1+ 13. Kh3 Qh1+ 14. Kg3 Kh6
15. Kg4 Qh2 16. g3 Qh1 17. Kf4 f6 18. Ne2 Qd1 19. Nd4 a5 20. g4 b4 21. axb4
axb4 22. Kg3 Qe1+ 23. Kg2 Kh7 24. Kh3 Kg7 25. Re2 Qf1+


The whole line was interactively made with Houdini 5 and Brainfish against alone for White playing Brainfish.

Engines with less nullmove pruning seem to have advantages playing for Black, Houdini here was in Tactical Mode, the 0-1- game I showed in the other posting was SugaR, less nullmove pruning too.

Output after Backward of the line above and 4...h4 (?):

[d]8/pp3pk1/6p1/3p4/2pN3P/P1P2PK1/1P2R1P1/6q1 b - - 0 1

Analysis by Brainfish 190317 64 POPCNT:

4...a6 5.Re5 Qf1 6.Re7 b6 7.Re2 b5 8.Kf4 Kf6 9.Kg3 Qd1 10.Kg4 Qc1 11.Kh3 Qh1+ 12.Kg3 Qf1 13.Kg4 Qd1 14.h5 gxh5+ 15.Kxh5 a5 16.Kg4 b4 17.axb4 axb4 18.Rc2 Qe1 19.Re2 Qf1 20.Rc2 Kg6 21.Kg3 f5 22.Re2 Qc1 23.Rc2 Qe1+ 24.Kh3 f4 25.Kh2 Kf6 26.Re2 Qd1 27.g3 Qd3 28.Rc2 fxg3+ 29.Kxg3 Qg6+ 30.Kf2 Qh6 31.Kg3 Qg5+ 32.Kh3 Qg6 33.Rg2 Qh5+ 34.Kg3 Qg5+ 35.Kh3 Qh6+ 36.Kg4 Qc1 37.Rc2 Qd1 38.Re2 Qa1 39.Rc2 Qg1+ 40.Kh4 Qb1 41.Kh3 Qh1+ 42.Kg3 Kg6 43.Re2
-+ (-1.75) Depth: 55/80 00:03:04 4743MN, tb=6779238

And after one more ply backward:

[d]8/pp3pk1/6p1/3p4/2pN4/P1P2PKP/1P2R1P1/6q1 w - - 0 1

Analysis by Brainfish 190317 64 POPCNT:

4.Re7 b5 5.Re2 Qf1 6.Re5 a6 7.Re3 Qb1 8.Re2 Qc1 9.Kf2 Kf6 10.Rc2 Qd1 11.Re2 Qa1 12.Kg3 Qg1 13.Re8 Qf1 14.Re3 Kg7 15.Re7 Kf8 16.Re3 g5 17.Re2 a5 18.h4 gxh4+ 19.Kxh4 Kg7 20.Kg4 Kg6 21.Kf4 f6 22.g4 Qc1+ 23.Kg3 Qg1+ 24.Rg2 Qe1+ 25.Kh2 b4 26.Re2 Qc1 27.axb4 axb4 28.Rc2 Qf1 29.Kg3 Qg1+ 30.Kh3 Kg7 31.Nf5+ Kf8 32.Nd4 Qf1+ 33.Kh4 Kf7 34.Re2 Qc1 35.Rc2 Qe1+ 36.Kh3
-+ (-1.63) Depth: 51/68 00:06:24 9996MN, tb=7076799

And one more ply backward:

[d]8/pp3pk1/6p1/3p4/2pN4/P1P2P1P/1P2RKP1/2q5 w - - 0 1

Analysis by Brainfish 190317 64 POPCNT:

3.Rc2 Qb1 4.f4 Qd1 5.Re2 a5 6.g3 Qh1 7.h4 Qb1 8.Rd2 Kh6 9.Kg2 Qe4+ 10.Kh3 Qh1+ 11.Rh2 Qf1+ 12.Rg2 f5 13.Kh2 Qd1 14.Kh3 Qh1+ 15.Rh2 Qf1+ 16.Rg2 Kh5 17.Nb5 Qe1 18.Rh2 Qe3 19.Rg2 Qe4 20.Rh2 Qb1 21.Rg2 Qh1+ 22.Rh2 Qf3 23.Nd4 Qe3 24.Re2 Qd3 25.Rf2 Qe4 26.Rd2 Qh1+ 27.Rh2 Qd1 28.Rf2 Qa1 29.Rh2 Qf1+ 30.Rg2 Qe1 31.Re2 Qb1 32.Rg2 Kh6 33.Kh2 Qe4 34.Rd2 Qe3 35.Re2
-/+ (-1.56) Depth: 49/75 00:01:55 2979MN, tb=1557957

[Nordlandia]

Mate in 19

[d]r2rn1n1/4pN2/b3p2q/1p2pP1P/pR1pBk1p/K4p1P/2PN1P2/2B5 w - - 0 1

Matefinder available for download ---->

http://chess.ultimaiq.net/stockfish.ht

[peter]

Mate in 19

[d]r2rn1n1/4pN2/b3p2q/1p2pP1P/pR1pBk1p/K4p1P/2PN1P2/2B5 w - - 0 1

Matefinder available for download ---->

http://chess.ultimaiq.net/stockfish.ht

[d]r2rn1n1/4pN2/b3p2q/1p2pP1P/pR1pBk1p/K4p1P/2PN1P2/2B5 w - - 0 1

Analysis by Brainfish 190317 64 POPCNT:
...
1.Nxh6 Nxh6 2.Bxa8 Rxa8 3.Nf1+ Kxf5 4.Bxh6 Nf6 5.Nd2
-+ (-3.65) Tiefe: 8/9 00:00:15 14kN
1.Bd3 e4 2.Nxe4+ Kxf5 3.Bxh6 Nxh6 4.Nxh6+ Kf4 5.Nf7 Rdc8 6.Rxd4
-+ (-2.46) Tiefe: 9/13 00:00:15 52kN
...
1.Bd3 e4 2.Bxe4 e5 3.Bd3 e4 4.Bxe4 Nef6 5.Bd3 Ne4 6.Bxe4 e5 7.Bd3 e4 8.Nxe4+ Kxf5 9.Bxh6 Nxh6 10.Nc5+ Kf6 11.Nxd8 Rxd8 12.Nxa6 Rd5 13.Nc7 Rxh5 14.Rxd4 Rc5 15.Nxb5 Nf7 16.Rf4+ Ke7 17.Nd4 Ne5 18.Bb5 Kd6 19.Rxh4 Ng6 20.Rh7 Nf4 21.Kxa4
+- (5.85) Depth: 27/51 00:00:23 204MN
1.Bd3
+- (5.92 ++) Depth: 28/55 00:00:24 231MN
...
1.Bd3
+- (127.75 ++) Depth: 28/60 00:00:36 537MN
1.Bd3 e4 2.Bxe4 e5 3.Bd3 e4 4.Bxe4 Ngf6 5.Bd3 Ne4 6.Bxe4 Nf6 7.Bd3 Ne4 8.Bxe4 Bb7 9.Bd3 Be4 10.Rxb5 Rd5 11.Rxd5 Qd6+ 12.Nxd6 Kg5 13.N2xe4+ Kxh5 14.Nf6+ exf6 15.Be4 Rg8 16.Bxf3+ Rg4 17.hxg4#
+- (#17) Depth: 28/60 00:00:36 543MN
...
1.Bd3 e4 2.Bxe4 e5 3.Bd3 e4 4.Bxe4 Ngf6 5.Bd3 Ne4 6.Bxe4 Nd6 7.Bd3 Ne4 8.Bxe4 Bb7 9.Bd3 Be4 10.Rxb5 Rd5 11.Rxd5 Qd6+ 12.Nxd6 Kg5 13.N2xe4+ Kxh5 14.Nf6+ exf6 15.Be4 Rg8 16.Bxf3+ Rg4 17.hxg4#
+- (#17) Depth: 46/60 00:00:52 970MN

Not so difficult, not an endgame and 2 moves shorter to mate.

[Nordlandia]

Stockfish assessment: -1.15

Code: Select all

3r2k1/pp3p2/4qpp1/2p5/2P5/5P2/PPQ3PP/R5K1 w - - 0 0

--------------

Stockfish assessment: +0.70

Code: Select all

2r3k1/pp4p1/7p/3R4/1P6/P5P1/5P1P/6K1 b - - 0 0