Answers.Body: <p>This game meets the criteria of Black plays the best move Nf6, and after one move, White has nothing better than a perpetual. However, it's probably not quite what you're looking for. If Black plays the second best move, Stockfish evaluates the position as +0.12, which is a rather slim advantage for White. So it's hardly the "only saving move". Furthermore, White has the option of not pursuing the perpetual and playing on - according to Stockfish, the resulting position is "nothing better than" the perpetual, but it's not really worse either.</p>
  
  <p>The Nf6 move that is relevant occurs on move 44 by black, and soon thereafter white perpetually checks black with their rook. 17 moves later a draw occurs.</p>
  
  <p>White was rated 2500, and Black was rated 2537. Both were grandmasters at the time.</p>
  
  <pre><code>[Event "Redbus KO"]
  [Site "Southend"]
  [Date "2002.04.01"]
  [Round "4.2"]
  [White "Ward, Chris G"]
  [Black "Lalic, Bogdan"]
  [Result "1/2-1/2"]
  [WhiteElo "2500"]
  [BlackElo "2537"]
  [ECO "A20"]
  [EventDate "2002.03.29"]
  [PlyCount "122"]
  [Source "ChessliB"]
  [SourceDate "2003.01.21"]
  [FEN ""]
  
  1.c4 e5 2.g3 Nf6 3.Bg2 c6 4.Nf3 e4 5.Nd4 d5 6.cxd5 Qxd5 7.Nc2 Qh5 8.h3 Bc5
  9.b4 Bb6 10.Bb2 Nbd7 11.Ne3 O-O 12.Nc3 Re8 13.Qc2 Qg6 14.b5 Bd4 15.bxc6 
  bxc6 16.Qa4 c5 17.Rb1 Nb6 18.Qc2 Bd7 19.a4 Bxc3 20.Bxc3 Bxa4 21.Qa2 Nfd7 
  22.h4 Qe6 23.Qxe6 Rxe6 24.h5 Bc6 25.h6 g6 26.O-O f5 27.Ra1 Na4 28.Bg7 Ndb6
  29.Rfc1 Rd8 30.Ra2 Bb5 31.Kf1 a6 32.Ke1 c4 33.Nc2 Red6 34.Na3 Nc5 35.f3 
  Nb3 36.Rcc2 e3 37.dxe3 Nd5 38.Nxc4 Rc6 39.Ne5 Re6 40.Rcb2 Nc5 41.Rd2 Red6 
  42.Kf2 Ne6 43.f4 Nxg7 44.hxg7 Nf6 45.Rxd6 Rxd6 46.Rc2 Kxg7 47.Rc7+ Kg8 48.
  Rc8+ Kg7 49.Rc7+ Kg8 50.Ra7 Nd7 51.Nf3 Nf6 52.Ne5 Nd7 53.Ra8+ Kg7 54.Ra7 
  Kg8 55.Ra8+ Kg7 56.Ra7 Kg8 57.Nf3 Nf6 58.Ne5 Nd7 59.Nf3 Nf6 60.Ne5 Nd7 61.
  Nf3 Nf6 ( 61...Nf6 32:+0.00 62.Ne5 Rd2 63.Ra8+ Kg7 64.Ra7+ Kg8) 1/2-1/2
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-06T21:08:39.660Z
Answers.Text: I was actually referring to the move 61...Nf6, but I now see that move happens a few times...
Answers.UserDisplayName: D M
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-05-06T04:01:20.513Z
Answers.LastActivityDate: 2019-05-06T18:21:19.863Z
Answers.LastEditDate: 2019-05-06T18:21:19.863Z
Answers.UserDisplayName: D M
Body: <p>My colleague Prof. Dr. S. writes a fictional story with symbolic elements involved.  One of them is a simultaneous game played by a grandmaster with a gifted schoolboy. Prof. S. wants to represent it by a real game by players of similar strength. But for some symbolic reasons, unknown even to the author, :-) the end of the game <em>must</em> match the following pattern. At the final stage Black finds a unique saving move ... Nf6 and after one move White has nothing better than a perpetual check. I failed to find such a game by Google and I am not acquainted with chess databases, so I ask here for a game instance matching the given pattern, preferable with mentioned strength of the players. Thanks.</p>
  
  <p><strong>Update (May 7).</strong> I have a talk with Prof. S. He thanks to all who offered help. Below are results of our discussion of the problem conditions. </p>
  
  <p>The move …Nf6 followed by a perpetual check is a necessary game condition. But between ... Nf4 and the start of the perpetual check (which we consider as the first check in the series) are allowed a few intermediate moves, preferable at most three (at most four  in the worst case). </p>
  
  <p>Prof. S. understands how hard is to find a required game and thinks that it is needed a lot of luck for this. If it will fail than then, as  already proposed @Brandon_J and @Scounged, there is an option to construct a fake game of sufficiently strong players (especially White) which satisfies the above conditions and does not looks artificial. In this case it is preferable to start a game from a move 1. d4.</p>
  
  <p>On the very worst case when even a construction will fail there is a option to construct only the final position, which looks as a plausible position from a game of sufficiently strong players.</p>
  
  <p>Unfortunately, the <a href="https://chess.stackexchange.com/a/24389/19031">game</a> between Ward and Lalic does not fit the purpose of Prof. S. He needs a <em>material</em> advantage for White which is kept after the move …Nf6. Nevertheless, also is required that this move is not an obvious, and this is a problem. The advantage, the bigger the better, but it can be sufficient for White to have a superfluous or a passed pawn. The aim of this condition is to provide for the amateur audience a game position which seems to be winning for White.</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T10:28:04.997Z
Comments.Text: Just to clarify, the moves are 1...Nf6 2. unknown moves by white/black 3. White gives perpetual?
Comments.UserDisplayName: user1583209
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T10:47:15.470Z
Comments.Text: @user1583209 1. Yes. 2. Only one move. 3. Yes.
Comments.UserDisplayName: Alex Ravsky
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T13:59:25.450Z
Comments.Text: @RewanDemontay I already tried to formulate the question as clear as I can (and this is already a result of a discussion with Prof. S.) and I can clarify requested details in comments. Concerning your previous comment, the 
  question problem is specific. It concerns a real game, but much more fits for chess composition. Namely, the given pattern should be satisfied verbatim. For instance, the amazing knight move has to be exactly ... Nf6 and no its alternatives are allowed.
Comments.UserDisplayName: Alex Ravsky
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T16:58:19.453Z
Comments.Text: Perhaps you would like a reasonably composed game from one of us?
Comments.UserDisplayName: Brandon_J
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T17:18:37.697Z
Comments.Text: This sort of thing is not easy to search for.  I can ask Stockfish whether a move was uniquely saving, but I'd need to narrow it down to a reasonably small number of games first. I can set a filter for games that ended in a draw and contain Nf6, but that's nearly half the games in the database. I can't search the database for "perpetual check", and who knows whether the perpetual was actually played - they could have agreed to a draw once it became obvious.
Comments.UserDisplayName: D M
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T17:41:17.857Z
Comments.Text: Well, I found a game between grandmasters where Black plays Nf6, which is the best move, and the players agree to a draw because after one move White has nothing better than a perpetual. The problem is that if Black doesn't play Nf6, he's only losing by about a tenth of a pawn - it may be the best move, but it's hardly the "only" saving move.
Comments.UserDisplayName: D M
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T17:43:10.543Z
Comments.Text: It should definitely be possible to construct a study satisfying your demands, but it may not be very easy.
Comments.UserDisplayName: Scounged
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-05T19:56:03.843Z
Comments.Text: Thanks for your comments. I’ll send a link to this thread to Prof. S. and ask him which options are satisfiable for him.
Comments.UserDisplayName: Alex Ravsky
Tags: <master-games><perpetual>
Title: Looking for a real game ending by ... Nf6! leading to a perpetual check by White
ThreadText: # Looking for a real game ending by ... Nf6! leading to a perpetual check by White
  
  (Asked by: username_0 on 2019-05-05)
  
  My colleague Prof. Dr. S. writes a fictional story with symbolic elements involved. One of them is a simultaneous game played by a grandmaster with a gifted schoolboy. Prof. S. wants to represent it by a real game by players of similar strength. But for some symbolic reasons, unknown even to the author, :-) the end of the game *must* match the following pattern. At the final stage Black finds a unique saving move ... Nf6 and after one move White has nothing better than a perpetual check. I failed to find such a game by Google and I am not acquainted with chess databases, so I ask here for a game instance matching the given pattern, preferable with mentioned strength of the players. Thanks.
  
  **Update (May 7).** I have a talk with Prof. S. He thanks to all who offered help. Below are results of our discussion of the problem conditions.
  
  The move …Nf6 followed by a perpetual check is a necessary game condition. But between ... Nf4 and the start of the perpetual check (which we consider as the first check in the series) are allowed a few intermediate moves, preferable at most three (at most four in the worst case).
  
  Prof. S. understands how hard is to find a required game and thinks that it is needed a lot of luck for this. If it will fail than then, as already proposed @Brandon\_J and @username_4, there is an option to construct a fake game of sufficiently strong players (especially White) which satisfies the above conditions and does not looks artificial. In this case it is preferable to start a game from a move 1. d4.
  
  On the very worst case when even a construction will fail there is a option to construct only the final position, which looks as a plausible position from a game of sufficiently strong players.
  
  Unfortunately, the [game](https://chess.stackexchange.com/a/24389/19031) between Ward and Lalic does not fit the purpose of Prof. S. He needs a *material* advantage for White which is kept after the move …Nf6. Nevertheless, also is required that this move is not an obvious, and this is a problem. The advantage, the bigger the better, but it can be sufficient for White to have a superfluous or a passed pawn. The aim of this condition is to provide for the amateur audience a game position which seems to be winning for White.
  
  **Tags:** master-games, perpetual
  
  > **Comments:**
  > **username_1**: Just to clarify, the moves are 1...Nf6 2. unknown moves by white/black 3. White gives perpetual?  
  > **username_0**: @username_1 1. Yes. 2. Only one move. 3. Yes.  
  > **username_0**: @RewanDemontay I already tried to formulate the question as clear as I can (and this is already a result of a discussion with Prof. S.) and I can clarify requested details in comments. Concerning your previous comment, the  question problem is specific. It concerns a real game, but much more fits for chess composition. Namely, the given pattern should be satisfied verbatim. For instance, the amazing knight move has to be exactly ... Nf6 and no its alternatives are allowed.  
  > **username_2**: Perhaps you would like a reasonably composed game from one of us?  
  > **username_3**: This sort of thing is not easy to search for.  I can ask Stockfish whether a move was uniquely saving, but I'd need to narrow it down to a reasonably small number of games first. I can set a filter for games that ended in a draw and contain Nf6, but that's nearly half the games in the database. I can't search the database for "perpetual check", and who knows whether the perpetual was actually played - they could have agreed to a draw once it became obvious.  
  > **username_3**: Well, I found a game between grandmasters where Black plays Nf6, which is the best move, and the players agree to a draw because after one move White has nothing better than a perpetual. The problem is that if Black doesn't play Nf6, he's only losing by about a tenth of a pawn - it may be the best move, but it's hardly the "only" saving move.  
  > **username_4**: It should definitely be possible to construct a study satisfying your demands, but it may not be very easy.  
  > **username_0**: Thanks for your comments. I’ll send a link to this thread to Prof. S. and ask him which options are satisfiable for him.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_3 on 2019-05-06. Score: 2
  
  This game meets the criteria of Black plays the best move Nf6, and after one move, White has nothing better than a perpetual. However, it's probably not quite what you're looking for. If Black plays the second best move, Stockfish evaluates the position as +0.12, which is a rather slim advantage for White. So it's hardly the "only saving move". Furthermore, White has the option of not pursuing the perpetual and playing on - according to Stockfish, the resulting position is "nothing better than" the perpetual, but it's not really worse either.
  The Nf6 move that is relevant occurs on move 44 by black, and soon thereafter white perpetually checks black with their rook. 17 moves later a draw occurs.
  White was rated 2500, and Black was rated 2537. Both were grandmasters at the time.
  [Event "Redbus KO"]
  [Site "Southend"]
  [Date "2002.04.01"]
  [Round "4.2"]
  [White "Ward, Chris G"]
  [Black "Lalic, Bogdan"]
  [Result "1/2-1/2"]
  [WhiteElo "2500"]
  [BlackElo "2537"]
  [ECO "A20"]
  [EventDate "2002.03.29"]
  [PlyCount "122"]
  [Source "ChessliB"]
  [SourceDate "2003.01.21"]
  [FEN ""]
  
  1.c4 e5 2.g3 Nf6 3.Bg2 c6 4.Nf3 e4 5.Nd4 d5 6.cxd5 Qxd5 7.Nc2 Qh5 8.h3 Bc5
  9.b4 Bb6 10.Bb2 Nbd7 11.Ne3 O-O 12.Nc3 Re8 13.Qc2 Qg6 14.b5 Bd4 15.bxc6 
  bxc6 16.Qa4 c5 17.Rb1 Nb6 18.Qc2 Bd7 19.a4 Bxc3 20.Bxc3 Bxa4 21.Qa2 Nfd7 
  22.h4 Qe6 23.Qxe6 Rxe6 24.h5 Bc6 25.h6 g6 26.O-O f5 27.Ra1 Na4 28.Bg7 Ndb6
  29.Rfc1 Rd8 30.Ra2 Bb5 31.Kf1 a6 32.Ke1 c4 33.Nc2 Red6 34.Na3 Nc5 35.f3 
  Nb3 36.Rcc2 e3 37.dxe3 Nd5 38.Nxc4 Rc6 39.Ne5 Re6 40.Rcb2 Nc5 41.Rd2 Red6 
  42.Kf2 Ne6 43.f4 Nxg7 44.hxg7 Nf6 45.Rxd6 Rxd6 46.Rc2 Kxg7 47.Rc7+ Kg8 48.
  Rc8+ Kg7 49.Rc7+ Kg8 50.Ra7 Nd7 51.Nf3 Nf6 52.Ne5 Nd7 53.Ra8+ Kg7 54.Ra7 
  Kg8 55.Ra8+ Kg7 56.Ra7 Kg8 57.Nf3 Nf6 58.Ne5 Nd7 59.Nf3 Nf6 60.Ne5 Nd7 61.
  Nf3 Nf6 ( 61...Nf6 32:+0.00 62.Ne5 Rd2 63.Ra8+ Kg7 64.Ra7+ Kg8) 1/2-1/2
  
  > **Comments:**
  > **username_3**: I was actually referring to the move 61...Nf6, but I now see that move happens a few times...  
  
  ---
  
  