Answers.Body: <p><a href="https://chess.stackexchange.com/a/14077/7297">Student T</a> gives an explicit answer, but you can also view it from a game-theoretical perspective.</p>
  
  <p>Suppose normal chess is a draw (or a win for black). Then, white can play 1. Ng1-f3 and Nf3-g1, effectively becoming black and the rest of the game is normal, so it is a draw (or a win for white).</p>
  
  <p>Suppose normal chess is a win for white. This will almost certainly involve moving a pawn two steps from its initial position within the first 10 moves, or moving a bishop, queen, rook or king. You can use your extra move to perform this move in two steps, e.g. e2-e3-e4 or Bf1-d3-e2.</p>
  
  <p>In any case, White will not lose the game.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-04T08:12:58.847Z
Answers.Text: That is a very elegant answer!
Answers.UserDisplayName: GloriaVictis
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Answers.CreationDate: 2016-04-04T08:39:17.233Z
Answers.Text: This is a non-constructive proof. You must be a mathematician!
Answers.UserDisplayName: Dag Oskar Madsen
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Answers.CreationDate: 2016-04-04T10:06:09.327Z
Answers.Text: This is not a proof. The knight manoeuvre cost two tempi, not only one. Thus it does not prove that Black has no winning strategy.
Answers.UserDisplayName: Sir Cornflakes
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Answers.CreationDate: 2016-04-04T10:38:22.260Z
Answers.Text: @jknappen - the second tempo is 'paid' by the extra move White gets. And DagOskarMadsen, you are right.
Answers.UserDisplayName: Glorfindel
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Answers.CreationDate: 2016-04-04T07:57:21.167Z
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Answers.LastEditDate: 2017-04-13T12:48:53.737Z
Answers.UserDisplayName: Glorfindel
Answers.Body: <p>Yes. 1.e4, then move the white Queen out to f3|g4|h5. Prepare for Qxf7+ then Qxe8 or Qxd7+ then Qxe8. Now white wins because the black king is gone.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-04T09:03:05.347Z
Answers.Text: Say 1.e4 Nf6. Can you win Black's king by force now? Or are you just going to grab a piece? Can you prove that White can win or draw with an extra piece?
Answers.UserDisplayName: bof
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Answers.Text: 2. e5 and your knight can't run (otherwise 3. e6 wins) so white can at least grab your knight without using his extra move.
Answers.UserDisplayName: jf328
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Answers.CreationDate: 2016-07-11T09:42:46.117Z
Answers.Text: 2.Bc4 can give Black some trouble.  1.e4 Nf6 2.Bc4 (threatens 3.Qh5,Qxf7#) g6 3.e5 (threatens 4.e6,exf7# or 4.Qf3,Qxf7# if the knight moves anywhere but d5, where it is lost.) e6 4.exf6. Now if 4…Qxf6 5.Qf3,Qxf6 and if anything else then 5.Qg4 threatens 6.Qxe6,Qxf7# or even just 6.Qxe6,Qxe8#. 5…Be7 doesn't prevent mate on f7, and 5…Qe7 or 5…Qf6 loses the queen. Also 5…d5 just loses to 6.Bb5,Bxe8#  Sacrificing the knight on d5 on move 2 or 3, followed by e6, seems best for Black, but probably still loses.
Answers.UserDisplayName: Jivan Scarano
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Body: <p>If you modify chess so that white gets to make one extra move within the first 10 moves, is it possible to show there is a non-losing strategy for white?</p>
  
Tags: <strategy><theory><chess-variants>
Title: Non-losing strategy for white
ThreadText: # Non-losing strategy for white
  
  (Asked by: username_0 on 2016-04-03)
  
  If you modify chess so that white gets to make one extra move within the first 10 moves, is it possible to show there is a non-losing strategy for white?
  
  **Tags:** strategy, theory, chess-variants
  
  
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  ## 2 answers
  
  ### Answer by username_1 on 2016-04-04. Score: 6 | Accepted answer
  
  [Student T](https://chess.stackexchange.com/a/14077/7297) gives an explicit answer, but you can also view it from a game-theoretical perspective.
  
  Suppose normal chess is a draw (or a win for black). Then, white can play 1. Ng1-f3 and Nf3-g1, effectively becoming black and the rest of the game is normal, so it is a draw (or a win for white).
  
  Suppose normal chess is a win for white. This will almost certainly involve moving a pawn two steps from its initial position within the first 10 moves, or moving a bishop, queen, rook or king. You can use your extra move to perform this move in two steps, e.g. e2-e3-e4 or Bf1-d3-e2.
  
  In any case, White will not lose the game.
  
  > **Comments:**
  > **username_2**: That is a very elegant answer!  
  > **username_3**: This is a non-constructive proof. You must be a mathematician!  
  > **username_4**: This is not a proof. The knight manoeuvre cost two tempi, not only one. Thus it does not prove that Black has no winning strategy.  
  > **username_1**: @jknappen - the second tempo is 'paid' by the extra move White gets. And DagOskarMadsen, you are right.  
  
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  ### Answer by username_5 on 2016-04-03. Score: 3
  
  Yes. 1.e4, then move the white Queen out to f3|g4|h5. Prepare for Qxf7+ then Qxe8 or Qxd7+ then Qxe8. Now white wins because the black king is gone.
  
  > **Comments:**
  > **username_6**: Say 1.e4 Nf6. Can you win Black's king by force now? Or are you just going to grab a piece? Can you prove that White can win or draw with an extra piece?  
  > **username_7**: 2. e5 and your knight can't run (otherwise 3. e6 wins) so white can at least grab your knight without using his extra move.  
  > **username_8**: 2.Bc4 can give Black some trouble.  1.e4 Nf6 2.Bc4 (threatens 3.Qh5,Qxf7#) g6 3.e5 (threatens 4.e6,exf7# or 4.Qf3,Qxf7# if the knight moves anywhere but d5, where it is lost.) e6 4.exf6. Now if 4…Qxf6 5.Qf3,Qxf6 and if anything else then 5.Qg4 threatens 6.Qxe6,Qxf7# or even just 6.Qxe6,Qxe8#. 5…Be7 doesn't prevent mate on f7, and 5…Qe7 or 5…Qf6 loses the queen. Also 5…d5 just loses to 6.Bb5,Bxe8#  Sacrificing the knight on d5 on move 2 or 3, followed by e6, seems best for Black, but probably still loses.  
  
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