Puzzle of the week #84

Chess Diagram: 


It is your turn to move and there is a very tempting option available. What do you do? Do you move right away, or do you resist the temptation and analyse the position and your options first? I remember back in my junior years our coaches used to say:
"Sit on your hands and don't touch a piece until you are sure of your move!"
Well, normally that was easy for them to say, but that move was so tempting, you could not get it out of your head. It is so true!... It requires practice game after game to refrain yourself from making hasty moves. Today's puzzle by Troitsky was presented to the public in 1910. Both sides are one move away from Queening. White has 2 extra Knights and it seems an easy task to score the win. Is it so simple indeed? Your tasks:
a) White to move and win;
b) What tactical elements is White using as part of his plan to win the game?
Total available points for this puzzle is 20. The answers will be published next week together with puzzle #85.

Puzzle #83 solution:
Jeremy's solution:
"a) This endgame position is very basic: it has only five pieces on the board, Black has two and White has three. It is White to move, so he has to move one of those three. White will not have enough material to win if there is a pawn trade; that leaves us with only the King or the Knight to move. If the King moves, then Black's King will go to b7, chasing the Knight away, and then "c7-c6" winning the pawn. That means that he has to move the Knight.
LINE 1 (Black does not take the Knight)
1.Nb6+!! Kb7 2.Nc4 Kc8 If 2... c6 3.b6 ... and the Black King must stay in the square
3.Kg3 Kd7 4.Kf4 Ke6 5.Ke4 Ke7 6.Kd5 Kd7 7.Ne5+ Ke7 8.Kc6 Kd8 9.Nf7+ Kc8 10.Ng5 Kb8 11.Ne6 Kc8 12.Nxc7 1-0
LINE 2 (Black takes the Knight) White has a winning King and pawn endgame:
1... cxb6 2.Kg3 Kb7 3.Kf4 Kc7 4.Ke5 Kd7 5.Kd5 ... (White wins the opposition) 5... Kc7 6.Ke6 Kc8 7.Kd6 Kb7 8.Kd7 Kb8 9.Kc6 Ka7 10.Kc7 ... 1-0
b) The elements to consider are: - the opposition in the King and pawn endgame - sufficient mating material"
Eugen adds: the third element can be found in LINE 1 above when the Black King must stay in the square. The element used by White is the rule of the square.

Correct solutions:
Jeremy - 19 points
Rick - 18 points
Wilson, Owen - 10 points
Andy Q - 9 points


Andy Q - 131 points
Rick - 115 points
Joshua - 71 points
Jeremy - 68 points
Wilson - 49 points
Karl, Alex Ge - 39 points
Owen - 34 points
James - 23 points
Katerina, Andy Y - 20 points
Marcus - 19 points
Nathaniel - 18 points


Knights and pawns endgame