I missed an important line in the above post! 1. c7 Nxe5 2. c8=Q+ Qf8+ 3. Qxf8+ Kxf8 4. a7 Nf7+! 5. Kh7!! Nxh8 (5. … Re8?? Ng6+!! checkmate) 6. a8=Q+ Re8 7. Qd5 1-0 (Queen against Rook & knight should be an easy win for White)
1. c7 N:e5 2. c8Q+ Qf8+ 3. Q:f8+ K:f8 seems forced. There are some tricks to the position – 4. a7 Nf7+ and now white doesn’t play 5. N:f7 because of …Re8 stopping and winning the a-pawn, but 5. Kh7 because if 5… Re8 6. Ng6#. This is also why it is necessary to promote the c-pawn first; after 4… Nf7+ 5. Kh7 Nd6 controls c8 with an easy win for black if he has not yet promoted the c-pawn.
Once white succeeds in promoting the a-pawn, he reaches a Q vs. R+N ending where all of black’s pawns are weak, so it looks like white should win.
This is all pretty straightforward to this point, but now it gets tricky. Black cannot put the rook on e8 immediately since white can play Nd8 blocking access to c8 while also protecting the c6 square. So, black must play Re6 first:
15. ….c2 16. Nc2 Rc2 17. h4 Kg7 and this is a fairly easy win for black since his king is in front of the connected pawns, and he will simply double attack the pawns one by one and win them with careful play.
Now, lets back up and see why 1.c7 is the superior pawn push (I couldn’t see it without working through the wrong move first myself:
This move doesn’t work in the previous line since black’s knight can cover c8 from d6, but now black is dead since white has a pretty mate in the key line:
Win for White!
1. c7 Nxe5
(What else to prevent Qc8+ checkmate? Kf8 also gets mated quickly)
2. c8=Q+ Qf8+
3. Qxf8+ Kxf8
4. a7! 1-0
c7 Kf8 (forced); else c8=Q#
c8=Q+ Ke7 (forced)
Ng6+ Kf7 (forced)
Qf8#
1. c7! Kf8 (1. … Kxh8 2. c8Q/R#) 2. Ng6+ Ke8 3. c8Q#
I missed an important line in the above post!
1. c7 Nxe5
2. c8=Q+ Qf8+
3. Qxf8+ Kxf8
4. a7 Nf7+!
5. Kh7!! Nxh8
(5. … Re8?? Ng6+!! checkmate)
6. a8=Q+ Re8
7. Qd5 1-0
(Queen against Rook & knight should be an easy win for White)
1. c7 N:e5 2. c8Q+ Qf8+ 3. Q:f8+ K:f8 seems forced. There are some tricks to the position – 4. a7 Nf7+ and now white doesn’t play 5. N:f7 because of …Re8 stopping and winning the a-pawn, but 5. Kh7 because if 5… Re8 6. Ng6#. This is also why it is necessary to promote the c-pawn first; after 4… Nf7+ 5. Kh7 Nd6 controls c8 with an easy win for black if he has not yet promoted the c-pawn.
Once white succeeds in promoting the a-pawn, he reaches a Q vs. R+N ending where all of black’s pawns are weak, so it looks like white should win.
Well, it has to be one of two moves- either a7 or c7. Let’s look at the wrong one first:
1. a7? Ne5 (clearing the f-file)
2. a8Q Qf8 (with check)
3. Qf8 Kf8
4. c7 Nf7
5. Nf7
This is all pretty straightforward to this point, but now it gets tricky. Black cannot put the rook on e8 immediately since white can play Nd8 blocking access to c8 while also protecting the c6 square. So, black must play Re6 first:
5. …..Re6
6. Kg5 Rc6
7. Ne5 Rc7
8. Nc4 Rd7 (if 9.Kg4 then Rd4)
9. Ne3 Rd4
10. a5 c4
11. a6 c3
12. a7 Ra4
13. a8Q Ra8
14. Kg4 Ra2
15. g3
Or 15.h4 Rg2! 16.Ng2 c2-+. Continuing:
15. ….c2
16. Nc2 Rc2
17. h4 Kg7 and this is a fairly easy win for black since his king is in front of the connected pawns, and he will simply double attack the pawns one by one and win them with careful play.
Now, lets back up and see why 1.c7 is the superior pawn push (I couldn’t see it without working through the wrong move first myself:
1. c7! Ne5
2. c8Q Qf8
3. Qf8 Kf8
4. a7 Nf7
5. Kh7!
This move doesn’t work in the previous line since black’s knight can cover c8 from d6, but now black is dead since white has a pretty mate in the key line:
5. …..Re8 (how else to stop a8?)
6. Ng6#!