Answers.Body: <p><strong>EDIT:</strong> Here is another mate-in-two problem with five legal black moves leading to five different checkmates. </p>
  
  <pre><code>   [Event "Apprenti Sorcier, 1992"]  
     [White "ACHBAR Selim"]
     [Black "mate in two"]
     [Result "1-0"]
     [SetUp "1"]
     [FEN "8/8/1R6/2p5/8/2Bk1NRN/3P4/K6B w - - 0 1"]
  
     1.Rb1! (1...Ke2 2.Nfg1#)(1...Ke4 2.Nh4#)(1...Kc2 2.Ne1#)(1...Kc4 2.Ne5#)(1...c4 2.Nd4#)
  </code></pre>
  
  <p>All five different mating moves are done with the same piece, which is very nice.</p>
  
  <hr>
  
  <p>Just to get this started; here is a mate-in-two problem with three possible black moves and three different checkmates.</p>
  
  <pre><code>  [Event "Grand Rapids Herald 1932 (643)"]
    [White "WURZBURG Otto B."]
    [Black "mate in two"]
    [Result "1-0"]
    [SetUp "1"]
    [FEN "8/Q7/2kp4/8/8/1K6/3R4/5B2 w - - 0 1"]
  
    1.Re2! (1...Kb5 2.Rc2#) (1...d5 2.Re6#)(1...Kd5 2.Bg2#) 
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-06-29T11:53:50.770Z
Answers.LastActivityDate: 2014-06-29T18:28:15.707Z
Answers.LastEditDate: 2014-06-29T18:28:15.707Z
Answers.UserDisplayName: Dag Oskar Madsen
Answers.Body: <p>I make a separate answer for my own constructions. I'm not a problem composer and don't claim any artistic value.</p>
  
  <p>In the following position black has 18 legal moves, and white has a unique mating move after each black move. The 18 mating moves are all different.</p>
  
  <pre><code>   [Title "Black to move"]
     [SetUp "1"]
     [FEN "kr5R/rb6/8/8/8/4p3/2K3B1/R6Q w - - 0 1"]
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-06-30T12:25:49.243Z
Answers.LastActivityDate: 2014-06-30T12:33:56.620Z
Answers.LastEditDate: 2014-06-30T12:33:56.620Z
Answers.UserDisplayName: Dag Oskar Madsen
Answers.Body: <p>So I looked this up in C. Jeremy Morse's <em>Chess Problems: Tasks and Records</em>,
  as I should have done before entering this fray.  The specific task posed by
  <em>I.J. Kennedy</em> is not addressed, but there are several problems that come close
  while pursuing some other goal.  In particular, a problem by Morse himself
  (#34, originally in <em>The Problemist</em> 1992), using the same three-lines
  scheme that <strong>Dag Oskar Marsden</strong> found independently, is easily modified to 
  attain <strong>21</strong> Black moves each answered by a different mate: </p>
  
  <pre><code>  [Title "Mate in 2 (C. Jeremy Morse 1992, adapted NDE 2016)"]
    [SetUp "1"]
    [FEN "5Q1R/P2p2K1/2bPP1p1/7r/3B1NN1/4p3/8/R5rk w - - 0 1"]
  </code></pre>
  
  <p>Again two White Queens, one provided by the key move 1 a8Q! 
  One mate appears on each of the 21 squares on the same rank, file, or
  diagonal as the bKh1.</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-04T02:08:56.470Z
Answers.LastActivityDate: 2016-04-04T02:08:56.470Z
Answers.UserDisplayName: Noam D. Elkies
Answers.Body: <p>This is answered in Sir Jeremy Morse's Chess Problems: Tasks and Records, already cited by Professor Elkies. In paragraph 2.4, Morse says &quot;The record for the total number of different White mates (and hence of variations also) in the two-mover is 24, shown in <strong>1</strong>, with multiple threats but only a few minor duals.&quot; (The problem Morse refers to is the same one in the 1st edition, published 1995, and the 3rd, published in 2016; I show it below.)</p>
  <p>If the duals are removed, 24 dual-free lines remain, ending in 24 different mates.</p>
  <pre><code>[Title &quot;Nenad Petrovic, The Problemist, 1946. #2&quot;]
  [FEN &quot;Q7/7P/3p2p1/2P1R3/1KN2pqp/1P4p1/r3P3/kr5R w - - 0 1&quot;]
  
  1. h8=Q! Ra7 2. Qxa7#
  (1... Ra6 2. Qxa6#)
  (1... Ra5 2. Qxa5#)
  (1... Ra4+ 2. Qxa4#)
  (1... Ra3 2. Qxa3#)
  (1... Rxh1 2. Qxh1#)
  (1... Rxa8 2. Qxa8#)
  (1... dxe5 2. Qxe5#)
  (1... Qf5 2. Rxf5#)
  (1... Qg5 2. Rxg5#)
  (1... Qh5 2. Rxh5#)
  (1... Qe6 2. Rxe6#)
  (1... Qd7 2. Re7#)
  (1... Qc8 2. Re8#)
  (1... d5 2. Rxd5#)
  (1... dxc5+ 2. Rxc5#)
  (1... f3 2. Re4#)
  (1... Qf3 2. Re3#)
  (1... Qxe2 2. Rxe2#)
  (1... Rg1 2. Rxg1#)
  (1... Rf1 2. Rxf1#)
  (1... Re1 2. Rxe1#)
  (1... Rd1 2. Rxd1#)
  (1... Rc1 2. Rxc1#)
  </code></pre>
  <p>So here we have the idea &quot;line-pinned black line-piece moves away from black king; white pinner captures it&quot; on a rank and on a file, as in Dag Oskar Madsen's and Prof. Elkies's problems, but not also on a diagonal. Instead, in 11 variations, White's other rook is used to discover a diagonal check, and must choose its destination accurately, either to interfere on the line a Black unit threatens to interpose on, or to capture that unit. Black uses a variety of means to make only one square work. wPe2 prevents 1. ... Qd1 and avoids a dual after 1. ... Re1.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2016-05-28T09:50:32.010Z
Answers.LastActivityDate: 2021-01-25T06:41:19.780Z
Answers.LastEditDate: 2021-01-25T06:41:19.780Z
Answers.UserDisplayName: Rosie F
Answers.Body: <p>Squeezing yet another mate from <strong>Dag Oskar Madsen</strong>'s construction,
  for a total of 19: </p>
  
  <pre><code>  [Title "Black to move"]
    [SetUp "1"]
    [FEN "R6Q/6B1/2p3K1/8/8/3pN3/rb6/kq5R w - - 0 1"] 
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-01T22:12:43.283Z
Answers.Text: 1 … d2+ 2 Bxb2??? Qxg6.
  
  Pc4 wouldn't work because all the long diagonal mates would fail to 2…c3.
Answers.UserDisplayName: Noam D. Elkies
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-01T22:26:35.290Z
Answers.Text: ah didn't notice d2 was check.
Answers.UserDisplayName: ryanyuyu
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-01T22:27:15.813Z
Answers.Text: Yes, that's the trick that allowed the extra mate.
Answers.UserDisplayName: Noam D. Elkies
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-01T17:54:43.447Z
Answers.LastActivityDate: 2016-04-01T17:54:43.447Z
Answers.UserDisplayName: Noam D. Elkies
Answers.Body: <p>How about this mate in two:</p>
  
  <p><img src="https://i.sstatic.net/akhI9.png" alt=""></p>
  
  <p>1.Nd4!!</p>
  
  <p>1...Bxd4 2.Qb1#</p>
  
  <p>1...Qxd4 2.Qxh7#</p>
  
  <p>1...Kxd4 2.Qb4#</p>
  
  <p>1...exd4 2.Qxd5#</p>
  
  <p>Everything else is answered by: 2.Rg4#</p>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2014-06-29T19:22:21.213Z
Answers.LastActivityDate: 2014-06-29T19:22:21.213Z
Answers.UserDisplayName: Fate
Answers.Body: <p>... and yet another mate, for a total of 20, at the cost of a few more
  White units including a second Queen:</p>
  
  <pre><code>  [Title "Black to move (after Dag Oskar Madsen)"]
    [SetUp "1"]
    [FEN "Q3Q2B/8/4P1K1/1P4p1/2N5/3pN3/rb6/kq5R w - - 0 1"] 
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-04-01T18:23:49.093Z
Answers.LastActivityDate: 2016-04-01T18:23:49.093Z
Answers.UserDisplayName: Noam D. Elkies
Body: <p>I'm looking for a chess position, hopefully not too contrived, in which it's Black's turn, he has several moves, but each one is refuted by a mate by White. </p>
  
  <p>I know I could take any mate-in-two problem, make White's first move and I'd be left with what I just described, but there's one more criterion: I'd like White's second (mating) move to be different for each of Black's possible moves. Or as many distinct mating moves as possible.</p>
  
  <p>Believe it or not, this is for teaching calculus.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-06-22T20:01:14.823Z
Comments.Text: PS: Tried to make this community wiki, couldn't find the checkbox.
Comments.UserDisplayName: I. J. Kennedy
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2014-06-29T16:57:19.090Z
Comments.Text: Most mate in two problems actually have this as a desideratum already. The more distinct mating moves on move 2, the better. So mate in two problems are actually a good place to start looking.
Comments.UserDisplayName: dfan
Tags: <problems><records>
Title: Position with the most (or many) distinct refutations?
ThreadText: # Position with the most (or many) distinct refutations?
  
  (Asked by: username_0 on 2014-06-22)
  
  I'm looking for a chess position, hopefully not too contrived, in which it's Black's turn, he has several moves, but each one is refuted by a mate by White.
  
  I know I could take any mate-in-two problem, make White's first move and I'd be left with what I just described, but there's one more criterion: I'd like White's second (mating) move to be different for each of Black's possible moves. Or as many distinct mating moves as possible.
  
  Believe it or not, this is for teaching calculus.
  
  **Tags:** problems, records
  
  > **Comments:**
  > **username_0**: PS: Tried to make this community wiki, couldn't find the checkbox.  
  > **username_1**: Most mate in two problems actually have this as a desideratum already. The more distinct mating moves on move 2, the better. So mate in two problems are actually a good place to start looking.  
  
  ---
  
  ## 7 answers
  
  ### Answer by username_2 on 2014-06-29. Score: 6
  
  **EDIT:** Here is another mate-in-two problem with five legal black moves leading to five different checkmates.
  
  ```
     [Event "Apprenti Sorcier, 1992"]  
     [White "ACHBAR Selim"]
     [Black "mate in two"]
     [Result "1-0"]
     [SetUp "1"]
     [FEN "8/8/1R6/2p5/8/2Bk1NRN/3P4/K6B w - - 0 1"]
  
     1.Rb1! (1...Ke2 2.Nfg1#)(1...Ke4 2.Nh4#)(1...Kc2 2.Ne1#)(1...Kc4 2.Ne5#)(1...c4 2.Nd4#)
  
  ```
  
  All five different mating moves are done with the same piece, which is very nice.
  
  ---
  
  Just to get this started; here is a mate-in-two problem with three possible black moves and three different checkmates.
  
  ```
    [Event "Grand Rapids Herald 1932 (643)"]
    [White "WURZBURG Otto B."]
    [Black "mate in two"]
    [Result "1-0"]
    [SetUp "1"]
    [FEN "8/Q7/2kp4/8/8/1K6/3R4/5B2 w - - 0 1"]
  
    1.Re2! (1...Kb5 2.Rc2#) (1...d5 2.Re6#)(1...Kd5 2.Bg2#) 
  
  ```
  
  
  ---
  
  ### Answer by username_2 on 2014-06-30. Score: 6
  
  I make a separate answer for my own constructions. I'm not a problem composer and don't claim any artistic value.
  
  In the following position black has 18 legal moves, and white has a unique mating move after each black move. The 18 mating moves are all different.
  
  ```
     [Title "Black to move"]
     [SetUp "1"]
     [FEN "kr5R/rb6/8/8/8/4p3/2K3B1/R6Q w - - 0 1"]
  
  ```
  
  
  ---
  
  ### Answer by username_3 on 2016-04-04. Score: 6
  
  So I looked this up in C. Jeremy Morse's *Chess Problems: Tasks and Records*,
  as I should have done before entering this fray. The specific task posed by
  *I.J. username_0* is not addressed, but there are several problems that come close
  while pursuing some other goal. In particular, a problem by Morse himself
  (#34, originally in *The Problemist* 1992), using the same three-lines
  scheme that **Dag Oskar Marsden** found independently, is easily modified to
  attain **21** Black moves each answered by a different mate:
  
  ```
    [Title "Mate in 2 (C. Jeremy Morse 1992, adapted NDE 2016)"]
    [SetUp "1"]
    [FEN "5Q1R/P2p2K1/2bPP1p1/7r/3B1NN1/4p3/8/R5rk w - - 0 1"]
  
  ```
  
  Again two White Queens, one provided by the key move 1 a8Q!
  One mate appears on each of the 21 squares on the same rank, file, or
  diagonal as the bKh1.
  
  
  ---
  
  ### Answer by username_4 on 2016-05-28. Score: 4
  
  This is answered in Sir Jeremy Morse's Chess Problems: Tasks and Records, already cited by Professor username_3. In paragraph 2.4, Morse says "The record for the total number of different White mates (and hence of variations also) in the two-mover is 24, shown in **1**, with multiple threats but only a few minor duals." (The problem Morse refers to is the same one in the 1st edition, published 1995, and the 3rd, published in 2016; I show it below.)
  
  If the duals are removed, 24 dual-free lines remain, ending in 24 different mates.
  
  ```
  [Title "Nenad Petrovic, The Problemist, 1946. #2"]
  [FEN "Q7/7P/3p2p1/2P1R3/1KN2pqp/1P4p1/r3P3/kr5R w - - 0 1"]
  
  1. h8=Q! Ra7 2. Qxa7#
  (1... Ra6 2. Qxa6#)
  (1... Ra5 2. Qxa5#)
  (1... Ra4+ 2. Qxa4#)
  (1... Ra3 2. Qxa3#)
  (1... Rxh1 2. Qxh1#)
  (1... Rxa8 2. Qxa8#)
  (1... dxe5 2. Qxe5#)
  (1... Qf5 2. Rxf5#)
  (1... Qg5 2. Rxg5#)
  (1... Qh5 2. Rxh5#)
  (1... Qe6 2. Rxe6#)
  (1... Qd7 2. Re7#)
  (1... Qc8 2. Re8#)
  (1... d5 2. Rxd5#)
  (1... dxc5+ 2. Rxc5#)
  (1... f3 2. Re4#)
  (1... Qf3 2. Re3#)
  (1... Qxe2 2. Rxe2#)
  (1... Rg1 2. Rxg1#)
  (1... Rf1 2. Rxf1#)
  (1... Re1 2. Rxe1#)
  (1... Rd1 2. Rxd1#)
  (1... Rc1 2. Rxc1#)
  
  ```
  
  So here we have the idea "line-pinned black line-piece moves away from black king; white pinner captures it" on a rank and on a file, as in username_2's and Prof. username_3's problems, but not also on a diagonal. Instead, in 11 variations, White's other rook is used to discover a diagonal check, and must choose its destination accurately, either to interfere on the line a Black unit threatens to interpose on, or to capture that unit. Black uses a variety of means to make only one square work. wPe2 prevents 1. ... Qd1 and avoids a dual after 1. ... Re1.
  
  
  ---
  
  ### Answer by username_3 on 2016-04-01. Score: 3
  
  Squeezing yet another mate from **username_2**'s construction,
  for a total of 19:
  
  ```
    [Title "Black to move"]
    [SetUp "1"]
    [FEN "R6Q/6B1/2p3K1/8/8/3pN3/rb6/kq5R w - - 0 1"] 
  
  ```
  
  > **Comments:**
  > **username_3**: 1 … d2+ 2 Bxb2??? Qxg6.  Pc4 wouldn't work because all the long diagonal mates would fail to 2…c3.  
  > **username_5**: ah didn't notice d2 was check.  
  > **username_3**: Yes, that's the trick that allowed the extra mate.  
  
  ---
  
  ### Answer by username_6 on 2014-06-29. Score: 2
  
  How about this mate in two:
  
  ![](https://i.sstatic.net/akhI9.png)
  
  1.Nd4!!
  
  1...Bxd4 2.Qb1#
  
  1...Qxd4 2.Qxh7#
  
  1...Kxd4 2.Qb4#
  
  1...exd4 2.Qxd5#
  
  Everything else is answered by: 2.Rg4#
  
  
  ---
  
  ### Answer by username_3 on 2016-04-01. Score: 2
  
  ... and yet another mate, for a total of 20, at the cost of a few more
  White units including a second Queen:
  
  ```
    [Title "Black to move (after username_2)"]
    [SetUp "1"]
    [FEN "Q3Q2B/8/4P1K1/1P4p1/2N5/3pN3/rb6/kq5R w - - 0 1"] 
  
  ```
  
  
  ---
  
  