100 percent corner

Imagine you have a cake and you cut it into 4 pieces. Each piece would be 25 percent of the cake. If you take one of those pieces and cut it into 4 smaller pieces, each of those would be 6.25 percent of the cake.

Now, let's say you are playing a game where you need to hit the ball into the corner of the field. The corner of the field is like that tiny piece of cake you cut into 4 smaller pieces. But in this case, hitting the ball into that tiny corner is like getting 100 percent of that small piece of cake.

So when people say "100 percent corner," they are talking about hitting the ball right into that tiny corner of the field, which is a very difficult thing to do but can lead to great success in the game.