paramount: Believe it or not, this is maybe one of the hardest puzzle i have ever seen. No wonder this puzzle becomes the last puzzle in the book of SCE-3.
Guess the right move!
Black to move and DRAW!!! 111...? (Sunday puzzle of course)
The first and natural logic 111...Ne6? loses because of the same pattern with the actual game due to 112.Qg4 threat.
112.Qg4 (Qh5# threatens) g6
113.Nxg6 Kg8...now, with the advantage of 2 pawns, and the king position is safe, this is a win for white although maybe you have to sweat a little bit to convert it.
What is the right answer?
112.Qxf8 Qc4+ (the point is to check back altogether with forking the knight,, with the result is white just up one pawn in the king+2 pawns vs king+pawn endgame and draw, it looks simple but ITS NOT) 113.Kg3 (Kh5 then Qe2+ and forcing to the line i will put)
I will make some notes here. There are 4 ways to check the white king 113...Qd3+/Qc3+/Qb3+/Qc7+, only one way to reach a salvation.
Lets try 113...Qc3+ 114.Qf3...now black has 2 ways to check the king 114...Qe1+/Qe5+...both loses, Qe1+ line is my line, Qe5+ line i take from SCE-3.
117.Kxe4...now its an easy win for white.
Now 114...Qe5+ (there is a reason why i put Qe5 line after Qe1, because this line will show you why the salvation move needed because there are the parallel patterns only one way to get the draw and one way to get the loss.
119.Qh5 (this h5 square is the reason why the next line needed) Kg8 120.Qh7#
The only way to get the draw is 113...Qd3!!, the only accurate move to take back the knight with the right position.
115.Kg4 Qb4!! (115...Qxe7? isnt works with the same reason as bad Qc3+ line 116.g6+!!...1-0)
119.Qxf8 Kxf8...DRAW. (for the dissidents, i let you check with tablebases)
See that after 114...Qb4!! if 115.Qh5 Qxe7 116.g6 Kg8 117.Qa8+ Qf8 118.Qd5+ Kh8!! then the f5 square is unaccessible for the queen to do the further check thats why Qc3 line isnt work...DRAW.
Of course there are many moves in between the lines, but i just put the most important lines and the easiest to comprehend. After i put those lines, surely you will have a slight comprehensions why 113...Qb3+/ Qc7+ also dont work, it would be too long to put those lines in here.
Other trifling matters for example like in the salvation line why 114.Kg4 or 118.Qc4+ also draw, you can easily check by yourself.
One last note (this line also i found myself).
In the bad 113...Qc3+ line, there is a paltry trap that you can pray hard for white to fall into it.
113...Qc3+? 114.Qf3 g6??! (two question marks with one exclamation, and pray for the exclamation mark works) 115.Qxc3??...sudden draw.