Answers.Body: <p>It looks that your variation should follow with Kh6 first, other than any Queen move.
  See some variations:</p>
  <pre><code>[Title &quot;Variations after 1...Rxd2+&quot;]
  [FEN &quot;r2r4/ppp2p1k/2n4P/4p3/P3n3/B1P1P2P/P1qPK2P/R6R b - - 0 1&quot;]
  
  1...Rxd2+ 2. Kf3 Rf2 3. Kg4 Kxh6 4. Bc1 Nf6+ 5. Kh4 Rf4+ 6. exf4 (6. Kg3 Qf2#) Qf2#
  (4. Bf8+ Rxf8 5. a3 Ne7 6. Rad1 Rf4+ 7. exf4 Qf2 8. Rdf1 Nf6#)
  (4. Kh4 Rf4+ 5. exf4 Qf2+ 6. Kg4 Qf4#)
  (4...Ne7 5. a3 Rf4+ 6. exf4 Qf2 7. fxe5+ Kg7 8. Rg1 Rh8 9. Bh6+ Rxh6 10. c4 Rh4#) 
  </code></pre>
  <p>I have been checking this for a few hours, it looks that after King to g4, ...Kxh6 gives the best chances. Black can also put a8-Rook into game from the d8-square, it can be sacrificed from d4 to open the position.</p>
  <p>EDITED for <code>4. Raf1</code> variations:</p>
  <pre><code>4. Raf1 Qd2, 5. Kh4 Qd8+, 6. Be7 Qxe7+, 7. Kg4 Qg5#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. Rxf7 Nf6+, 10. Rxf6+ Rxf6 11. a3 Rf5#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. h5 Nf2+ 10. Kh4 Qf4#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. h5 Nf2+ 10. Rxf2 Qxf2 11. a3 Rd8 12. a5 Rd2 13. c4 Qf4+ 14. Kh3 Rxh2#
  4. Raf1 Qd2, 5. Rhg1 Qxe3 6. Bc1 Qxc1 7. Rxc1 Rf4#
  4. Raf1 Qd2, 5. Rhg1 Qxe3 6. Bc1 Qxc1 7. Rxf2 Qxg1+ 8. Kf3 Qxf2+ 9. Kxe4 Rd8 10. a3 Qf4# 
  </code></pre>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T17:09:50.583Z
Answers.Text: @SecretAgentMan thanks for editing. However, the variations I have shared should be started after the white King goes to g4. I don't see the variations I have shared properly.
Answers.UserDisplayName: Baris Ozensel
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T19:03:59.207Z
Answers.Text: The moves are .. Rxd2+, Kf3 Rf2+, Kg4, as explained in the question. Then the variations I shared starts with .. Kh6. Thanks.
Answers.UserDisplayName: Baris Ozensel
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T20:09:39.277Z
Answers.Text: @SecretAgentMan For the variation starting with Bf8+, you need to specify which rook moves to d1. I assume it's the a rook, so it should be 6. Rad1 Rf4+ 7. exf4 Qf2 8. Rdf1 Nf6#
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T20:22:35.667Z
Answers.Text: @justhalf, this is correct. Thanks.
Answers.UserDisplayName: Baris Ozensel
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T23:07:50.820Z
Answers.Text: @BarisOzensel I apologize for the repeated screwups...just trying to help.  I hope it is fixed now.
Answers.UserDisplayName: SecretAgentMan
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T03:37:18.673Z
Answers.Text: How would you handle 4. Raf1?
Answers.UserDisplayName: justhalf
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T07:52:29.307Z
Answers.Text: @justhalf, I think that in that case the idea should be playing the Queen-d2 with the thread from Queen-d8. Because white king can move to h5-square anytime. After Queen-d2, incase of any other move Queen should take e3 pawn. I have edited my post with the variations starts with 4. Raf1?. I have to admit that this is kind of tough question, and realized that light squares are so important :)
Answers.UserDisplayName: Baris Ozensel
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T11:10:26.033Z
Answers.Text: In the variation starting with 4.Bf8, instead of 8.Rdf1?, 8.fe5! seems problematic.
Answers.UserDisplayName: Evargalo
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-20T15:39:14.373Z
Answers.Text: I don't think it is problematic. In case of moving fxe5, the answer should be playing f6. f6-pawn can't be captured as there is a mate with Nxf6. In case of Rhf1, Queen moves to e3. See some variations. 8.fe5 f6, 9. Rhf1 Qe3 10. Rf3 Qg5#. (10. Rd7 Nf2+ 11. Rxf2 Qxf2, 12. Rxe7 Qg1+ 13. Kh4 Qg5#) ((13. Kf5 fxe5+, 14. Kxe5  Qe3+, 15. Kd5 Qxe7)) Then you have Rook and Queen to check mate. There are many variations if you consider each move. I have just shared some of them. Back to question, it looks that Kh6 move gives the best chances. Thanks.
Answers.UserDisplayName: Baris Ozensel
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2022-04-19T14:49:56.983Z
Answers.LastActivityDate: 2022-04-20T12:50:30.823Z
Answers.LastEditDate: 2022-04-20T12:50:30.823Z
Answers.UserDisplayName: Baris Ozensel
Body: <p>In a <a href="https://www.youtube.com/watch?v=k_XXjjunU58" rel="nofollow noreferrer">recent Youtube video</a>, the black player reaches the following position</p>
  <pre><code>[White &quot;NN&quot;]
  [Black &quot;Chess Simp&quot;]
  [FEN &quot;r2r4/ppp2p1k/2n4P/4p3/P3n3/B1P1P2P/P1qPK2P/R6R b - - 0 1&quot;]
  
  1... Rxd2+ 2.Kf3 Rf2+ (2.Kf1 Rxh2 3.Rxh2 Qxh2 {And mate to follow on the second rank.}) (2.Ke1 Rf2 {White cannot stop checkmate on d2.}) 3.Kg4 Qd2 {The queen joins the attack via e3 or d8}
  </code></pre>
  <p>Now, obviously black is completely winning and under normal circumstances has mate in 4. However, due to the constraints of a self-imposed challenge, black is only allowed to move pieces and pawns to dark squares. Nevertheless, the overwhelming material advantage should lead to checkmate soon. I've put what I think are the best continuations for black, but I'm having trouble finding a forced checkmate in the Kf3 line. Any help?</p>
  
Tags: <checkmate><puzzles>
Title: Find a forced checkmate on dark squares only
ThreadText: # Find a forced checkmate on dark squares only
  
  (Asked by: username_0 on 2022-04-15)
  
  In a [recent Youtube video](https://www.youtube.com/watch?v=k_XXjjunU58), the black player reaches the following position
  
  ```
  [White "NN"]
  [Black "Chess Simp"]
  [FEN "r2r4/ppp2p1k/2n4P/4p3/P3n3/B1P1P2P/P1qPK2P/R6R b - - 0 1"]
  
  1... Rxd2+ 2.Kf3 Rf2+ (2.Kf1 Rxh2 3.Rxh2 Qxh2 {And mate to follow on the second rank.}) (2.Ke1 Rf2 {White cannot stop checkmate on d2.}) 3.Kg4 Qd2 {The queen joins the attack via e3 or d8}
  
  ```
  
  Now, obviously black is completely winning and under normal circumstances has mate in 4. However, due to the constraints of a self-imposed challenge, black is only allowed to move pieces and pawns to dark squares. Nevertheless, the overwhelming material advantage should lead to checkmate soon. I've put what I think are the best continuations for black, but I'm having trouble finding a forced checkmate in the Kf3 line. Any help?
  
  **Tags:** checkmate, puzzles
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2022-04-19. Score: 4
  
  It looks that your variation should follow with Kh6 first, other than any Queen move.
  See some variations:
  
  ```
  [Title "Variations after 1...Rxd2+"]
  [FEN "r2r4/ppp2p1k/2n4P/4p3/P3n3/B1P1P2P/P1qPK2P/R6R b - - 0 1"]
  
  1...Rxd2+ 2. Kf3 Rf2 3. Kg4 Kxh6 4. Bc1 Nf6+ 5. Kh4 Rf4+ 6. exf4 (6. Kg3 Qf2#) Qf2#
  (4. Bf8+ Rxf8 5. a3 Ne7 6. Rad1 Rf4+ 7. exf4 Qf2 8. Rdf1 Nf6#)
  (4. Kh4 Rf4+ 5. exf4 Qf2+ 6. Kg4 Qf4#)
  (4...Ne7 5. a3 Rf4+ 6. exf4 Qf2 7. fxe5+ Kg7 8. Rg1 Rh8 9. Bh6+ Rxh6 10. c4 Rh4#) 
  
  ```
  
  I have been checking this for a few hours, it looks that after King to g4, ...Kxh6 gives the best chances. Black can also put a8-Rook into game from the d8-square, it can be sacrificed from d4 to open the position.
  
  EDITED for `4. Raf1` variations:
  
  ```
  4. Raf1 Qd2, 5. Kh4 Qd8+, 6. Be7 Qxe7+, 7. Kg4 Qg5#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. Rxf7 Nf6+, 10. Rxf6+ Rxf6 11. a3 Rf5#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. h5 Nf2+ 10. Kh4 Qf4#
  4. Raf1 Qd2, 5. Rxf2 Qxf2, 6. Bf8+ Rxf8, 7. h4 Qxe3, 8. Rf1 Ne7, 9. h5 Nf2+ 10. Rxf2 Qxf2 11. a3 Rd8 12. a5 Rd2 13. c4 Qf4+ 14. Kh3 Rxh2#
  4. Raf1 Qd2, 5. Rhg1 Qxe3 6. Bc1 Qxc1 7. Rxc1 Rf4#
  4. Raf1 Qd2, 5. Rhg1 Qxe3 6. Bc1 Qxc1 7. Rxf2 Qxg1+ 8. Kf3 Qxf2+ 9. Kxe4 Rd8 10. a3 Qf4# 
  
  ```
  
  > **Comments:**
  > **username_1**: @username_3 thanks for editing. However, the variations I have shared should be started after the white King goes to g4. I don't see the variations I have shared properly.  
  > **username_1**: The moves are .. Rxd2+, Kf3 Rf2+, Kg4, as explained in the question. Then the variations I shared starts with .. Kh6. Thanks.  
  > **username_2**: @username_3 For the variation starting with Bf8+, you need to specify which rook moves to d1. I assume it's the a rook, so it should be 6. Rad1 Rf4+ 7. exf4 Qf2 8. Rdf1 Nf6#  
  > **username_1**: @username_2, this is correct. Thanks.  
  > **username_3**: @username_1 I apologize for the repeated screwups...just trying to help.  I hope it is fixed now.  
  > **username_2**: How would you handle 4. Raf1?  
  > **username_1**: @username_2, I think that in that case the idea should be playing the Queen-d2 with the thread from Queen-d8. Because white king can move to h5-square anytime. After Queen-d2, incase of any other move Queen should take e3 pawn. I have edited my post with the variations starts with 4. Raf1?. I have to admit that this is kind of tough question, and realized that light squares are so important :)  
  > **username_4**: In the variation starting with 4.Bf8, instead of 8.Rdf1?, 8.fe5! seems problematic.  
  > **username_1**: I don't think it is problematic. In case of moving fxe5, the answer should be playing f6. f6-pawn can't be captured as there is a mate with Nxf6. In case of Rhf1, Queen moves to e3. See some variations. 8.fe5 f6, 9. Rhf1 Qe3 10. Rf3 Qg5#. (10. Rd7 Nf2+ 11. Rxf2 Qxf2, 12. Rxe7 Qg1+ 13. Kh4 Qg5#) ((13. Kf5 fxe5+, 14. Kxe5  Qe3+, 15. Kd5 Qxe7)) Then you have Rook and Queen to check mate. There are many variations if you consider each move. I have just shared some of them. Back to question, it looks that Kh6 move gives the best chances. Thanks.  
  
  ---
  
  