A tiebreak in tennis is a special way to conclude a set when the score between players becomes equal, usually 6:6. Imagine that players are fighting for victory in the set, but neither can get ahead of the other by two games. To determine the winner without endless games, this format was invented.
The tiebreak works like this: players take turns serving the balls, and the winner is the one who first scores 7 points with a difference of two or more points. It's like a little “game within a game” that helps quickly resolve the situation when the forces are equal. In other words, a tiebreak is like an extra round in a match where the true winner is revealed.
For example, if one of the players is leading 6:3 in the tiebreak and then loses a few points, the intrigue remains: will he finish the tiebreak first, or will his opponent catch up and possibly even win? The tiebreak is such an intense part of the game that always keeps the spectators on the edge of their emotions.