All the best players of the world in 1929 played in an international tournament in Karlsbad, Czech Republic.

The position below is from Edgar Colle of Belgium and Ernst Gruenfeld of Austria.

The position is simple yet so difficult such that even the great Gruenfeld found no salvation for Black and resigned.

Indeed, it looks that Black loses.

But believe it or not, Black draws.

Analysis of this simple position is extremely difficult but if we were to use the technique of counting - as advocated by Likesforest in his blog "How to play games brilliantly - it simplifies everything.

Let's look at LINE #1 where Black's K goes to promote his a-pawn. This line loses for Black because:

Black would need 9 moves to queen his a-pawn (1...Kd3, 2...Kc4, 3....Kb4, 4....Kxa4, 5...Kb3, 6....a4, 7....a3, 8....a2 and 9....a1=Q  

While White would only need 7 moves to Q his h-pawn: 1.Kg5, 2.Kxa5, 3.Kb6, 4.a5, 5.a6, 6.a7, 7. a8=Q.  

Now LINE #2  where Black's K shadows the White K.

After 1....Kd3 2.Kg5 Ke4 3.Kxh5 Kf5 4.Kh6 Kf6 5.h5 Kf7 6.Kg5 Kf7 7.Kf5 Kh6, we start counting here:

It will take White 5 moves to get the a-pawn: 1.Ke5, 2.Kd5, 3.Kc5, 4.Kb5, 5.Kxa5.

It will take Black 5 moves also to reach the square d8 Blackdraws 1...Kxh5, 2... Kg5, 3...Kf6, 4....Ke6 and 5....Kd8.

On the 5th move White's K would be at a5 and Black's at d8. White can't prevent Black's K from going to the square a8 without getting himself imprisoned: 6.Ka6 Kc8 7.Ka7 Kc7 and all that Black needs to do to draw is shuffle the K back and forth between the squares c7 and c8.  Otherwise Black's K goes to the a8 square where he'll be in a fortress.  

So Black draws. 

A position extremely difficult to analyse but made simple and easy thru the technique of counting (For more information on "counting", see the blog of Likesforest called "HOW TO PLAY GAMES BRILLIANTLY".
 

nice lesson GM

I approached it in a different way, having read Dvoretsky's chapter on the subject (opposing a-pawn+1 additional pawn for white). The basic idea is to define the below as the normal position. It is drawn.

Now to the point of this idea. If the white rook pawn has passed the middle line, it's always a win. If it's not, then count tempi. -1 for every step behind the midline the pawns are, +1  for every step behind the c8-h3 diagonal the extra pawn is, -1 for every square ahead it is. Finally, +1 if whites king is ahead of the pawn rather than beside it. positive sum means white wins, else drawn.

Now, let's demonstrate with the position after 3...Kf5 in the above puzzle: pawn is at h4, +1 for black. King ahead of pawn, +1 for white. Pawns separated be the middle line. Sum 0, meaning it's draw. Black gets back to c8 in time. Handled this way, it's rather simple. Without the evaluation rule, it certainly isn't.

The idea behind the seemingly arbitrary rule about the h3-c8 diagonal is that, could black take the pawn on it he has an immediate path to the drawing square c8.