The only method you need to know for figuring out the Opposition

What is opposition anyway?

Currently in Wikipedia, it is defined as following:

Opposition is a situation in which two kings are two squares apart on the same rank or file. Since kings cannot move adjacent to each other, each king prevents the other's advance, creating a mutual blockade. In this situation, the player not having to move is said to have the opposition.

That's quite a formal definition that could fly over your head, let me illustrate by an elementary example:

If it is white's turn, black is said to have the opposition; if it is black's turn, white is said to have the opposition. In this crucial endgame (that all serious chess players should know by heart) the opposition decides the game - white to move draws; black to move wins for white. Knowing the concept of opposition and how to obtain it plays an essential role in many endgames.

Diving deeper

So the opposition is the name for the situation where the kings stare at each other, with one square separating the two monarchs, easy enough. However, the situation can become more complicated than that - there are also a diagonal and a distant opposition, and an opposition without a direct connection as well. The traditional way to determine an opposition would be with methods such as counting the orthogonal or diagonal squares to amount to an odd number, or visualizing a magic square with all corners of the square being of the same color. Not rocket science, but you don't really need those methods...

All you need is a raster

Let me show you a method which covers all of that and is much less of mental gymnastics. A picture is worth a thousand words:

Every opposition square with relation to the black king is visualized with a ring. Turns out, you simply need to visualize such a raster, and you immediately know what are the squares where you will achieve opposition. This is mindlessly easy to do. In the figure, we can immediately determine that if white were to move here, they would always lose the opposition since the king can't move to a "ring". Let me give you another example:

If it was white to move, we'd know that Kc3, Kc5, Ke3 and Ke5 would achieve opposition while Kc4, Kd3, Kd5 and Ke4 would hand the opposition to black.

Applied opposition

That was super easy! Let's finish with a more complicated example of applied opposition:

In the end, I should mention that chess is a complex game. While opposition is a useful tool in many positions, you can (and will!) lose (seemingly) level king endgames despite you gaining the opposition. Try to always base your moves on concrete continuations in your games.