Some top engines solve this instantly, but Humans ?

[Chessqueen]

Hello:

I got the key ideas on the second position, trying to stalemate the white king with c6 and b5 while getting rid of the white rook and the h-pawn. Nice indeed!

I searched the first position. The original post and the key word is swindle: black is winning (white is lost in 19 moves according to Shredder online EGTB) but in this case rushing the a-pawn builds a draw by stalemate or a standard draw, so a2 is an 'avoid move' at some moment. The intended solutions are here:

Jammo's Chess Puzzle #51

1. Nb3 a2? 2. Nc1! a1=Q (½-½) Draw by stalemate.
1. Nb3 a2? 2. Nc1! a1=R (½-½) Draw by stalemate.
1. Nb3 a2? 2. Nc1! a1=B (½-½) Draw.
1. Nb3 a2? 2. Nc1! a1=N 3. Nb3! (½-½) Draw.

I have followed a kind of 'chess notation approach' according to 'chess annotation symbols' article at Wikipedia: '?' for a move that converts a win into a draw, a draw into a lose or a win into a lose; and '!' for the only legal move that does not worsen the result of the playing side (only move that wins on a won position or only move that draws in a drawn position).

The web wrongly quotes the game Firmian - Smejkal, Tallinn 1971. According to ChessGames, white side was not Nick de Firmian but Semyon Abramovich Furman, so Furman - Smejkal, Tallinn 1971:

Semyon Abramovich Furman vs Jan Smejkal, Tallinn (1971)

[pgn]
[Event "Tallinn"]
[Site "Tallinn EST"]
[Date "1971.02.26"]
[EventDate "?"]
[Round "5"]
[Result "0-1"]
[White "Semyon Abramovich Furman"]
[Black "Jan Smejkal"]
[ECO "D76"]
[WhiteElo "?"]
[BlackElo "?"]
[PlyCount "188"]

1.d4 Nf6 2.c4 g6 3.g3 Bg7 4.Bg2 d5 5.cxd5 Nxd5 6.Nf3 O-O 7.O-O
Nb6 8.Nc3 Nc6 9.e3 Re8 10.Nd2 e5 11.d5 Ne7 12.e4 c6 13.Nb3
cxd5 14.exd5 Nf5 15.Nc5 Nd6 16.b3 e4 17.Bd2 f5 18.Rc1 Nf7
19.Re1 Nxd5 20.Nxd5 Qxd5 21.f3 b6 22.Na4 Bb7 23.fxe4 Qd4+
24.Be3 Qxd1 25.Rexd1 Bxe4 26.Bxe4 Rxe4 27.Bf2 Re7 28.Nc3 Ne5
29.h3 Rae8 30.Kf1 Nf3 31.Nd5 Re2 32.Nc7 R8e7 33.Rd8+ Kf7
34.Nd5 Nd2+ 35.Kg1 Nf3+ 36.Kf1 Nd2+ 37.Kg1 Bb2 38.Rd1 Re8
39.Rxe8 Kxe8 40.Nf4 Nf3+ 41.Kg2 Rd2 42.Rxd2 Nxd2 43.g4 Kd7
44.gxf5 gxf5 45.Nd3 Bc3 46.Be3 Kd6 47.Kf2 Ne4+ 48.Kf3 Bf6
49.Bf4+ Kd7 50.Bb8 a5 51.Be5 Bd8 52.Ke3 Ng5 53.Nf4 Ne6 54.Nh5
Bg5+ 55.Kf3 Kc6 56.Ng3 Kd5 57.Bb2 Nd4+ 58.Bxd4 Kxd4 59.Nxf5+
Kc3 60.Ke4 Kb2 61.Kd3 Kxa2 62.Kc2 Ka3 63.Nd4 Kb4 64.Ne6 Be7
65.Nf4 Kc5 66.Kd3 Bf6 67.Ng2 Kb4 68.Kc2 Kc5 69.Kd3 b5 70.Ne3
Bg5 71.Nc2 Bf6 72.Ne3 Bb2 73.Kc2 Bd4 74.Nf1 Bf6 75.Nd2 Kd4
76.Nb1 Be5 77.Nc3 Kc5 78.Ne4+ Kd5 79.Ng5 h6 80.Nf3 Ke4 81.Nd2+
Kf4 82.Kd3 Kg3 83.h4 h5 84.Ke2 a4 85.bxa4 bxa4 86.Nc4 Bf6
87.Kf1 Bxh4 88.Kg1 Be7 89.Kh1 Bc5 90.Nd2 a3 91.Ne4+ Kf3
92.Nxc5 a2 93.Nb3 Ke4 94.Kg2 Kd5 0-1
[/pgn]

White to move just after black's 90th move.

Regards from Spain.

Ajedrecista.

Yes you are correct as far as the players name, and Furman resigned and for most of the spectator, the final was rather dull, Except for Mikhail Tal who was watching and calculating on his head what would have been the best response for Furman. Tal approached the board after the game's that you posted here and asked " Smejkal, " What would you have done after 91. Nb3?! instead of the actual move 91. Ne4+ ?? Tal Knew what would have been the best response to 91. Nb3! which is NOT 92. a2?? but Tal who knew that most humans are impatience, and in certain position when you play an unusual response and NOT the obvious, they will play NOT the best move due to fear factor and nerve, and finally their need to stay in control. So when Smejkal responded Why pawn to a2 of course, then Tal knowing that that was NOT the best response said to Smejkal Ah with a twinkle in his Eye. "Then you would only have drawn." Remember that these were two human GMs playing NOT computer. And some people here immediately grab their computers and even used endgame TB to prove that 92. a2 was NOT the best response, keep in mind that TAl a former World Champion knew at the moment that he asked the question which was the best response.

PS: I also stated here on the title that Some Top Engines solves this instantly, but Humans ? meaning not all humans. Also before I posted the 2nd position I clearly wrote this which some of you missed it altogether " A Rook down how can you save from losing this game,which mean how can you try to save this losing position, remember playing versus human even Low or middle GM like that one that actually played this game, it might NOT work against top engines." Meaning it is NOT meant for computer to find the best moves since back then Computer were too weak and the point is that humans under pressure blunder even GMs. Therefore, please stop using computer and TB for positions that the poster specifically write down or imply that it is NOT for computer to solve it. I guarantee that if you ask 10 low or middle GMs what would they do after 91.Nb3! they will take a few second and respond that same way, well I will simply push my pawn to 92. a2?? and promote Tal at that time being a former World Champion was like GM Vishy Anand nowadays watching a game between two middle class FIDE Rated 2500 to 2600. But these are the consequences

1. Nb3 a2? 2. Nc1! a1=Q (½-½) Draw by stalemate.
1. Nb3 a2? 2. Nc1! a1=R (½-½) Draw by stalemate.
1. Nb3 a2? 2. Nc1! a1=B (½-½) Draw.
1. Nb3 a2? 2. Nc1! a1=N 3. Nb3! (½-½) Draw.

[Chessqueen]

[quote=Chessqueen post_id=855209 time=1596809498 user_id=10732]
This is another position that stuck into my mind from the book The Complete Chess Swindler by GM David Smerdon. Please try to solve it without computer.

[d]2k5/1pp4R/4N3/2P5/r7/1pb3P1/6KP/8 w - - 0 1

[Chessqueen]

This is another position that stuck into my mind from the book The Complete Chess Swindler by GM David Smerdon. Please try to solve it without computer.

[d]2k5/1pp4R/4N3/2P5/r7/1pb3P1/6KP/8 w - - 0 1

I see that even if you used your computer which recommend to take the pawn on c7 the Black king simply move to b8 and there is no way to stop the b pawn from promoting. But I searched on youtube and I will give you the solution, my online instructor told me that in order to always find the best move you have to try all your candidate pieces and do NOT forget pawns moves. So for this position all that you really had to do was try all your possible moves after Rook take on c7, and also try with your Knight, and finally try moving your pawn and Abracadabra, that is exactly what most top GM do they try all their option and candidate moves until they find the best one