"Hidden" feature of the knight
Hi, guys!
Today I want to share with you one very interesting feature of the knight and show you one instructive endgame position.
In the position above it's black to move and if black wants to make a draw they have to blockade white king on a8. There are two moves which accomplish this goal: Kc8 and Kc7. One makes a draw and another loses. How to decide which one to pick? Feel free to think about it yourself first before reading the answer.
It's almost impossible to calculate an outcome here by brute force - white have to many options. But if you know one little fuature then it's very simple. Correct move here is Kc7. We have to put our king on the square of the color of the knight. Why? Because knight has a feature which I'd say in this case is rather a bug. It's changing colors on every move. If knight is on a dark square like in example above then on the next move it'll be on a light square and then on a dark square again and etc.
Now, knowing this bug let's try to understand why our position is a draw after Kc7. First of all white can only make moves with the knight. Their king and the pawn are blockaded. The knight from a dark square can only jump to a light square and attack dark squares. What does it mean in our case? It means, that knight from g1 will go to a light square after what black king will go to the light c8 square, then the knight goes again to any dark square and black king returns to the dark c7 square again. It means that the king and the knight will always remain on the same color complex after blacks responce to a move by white. Now, what does it mean? It means that whenever knight comes to attack c7 or c8 square it's ALWAYS going to be a check to black king after what black king will be able successfully come to another square. Once again, why it's so? Because if black king is on c7 then white knight can only be on ANY light square and it's either check to black king after which he can go to c8 or knight is far away and it causes not problems. If black king is on c8 then white knight can only be on ANY dark square this time with the same effect. Repetition -->draw.
