What is Tiebreak??

At a score of 6-6, a set is often determined by one more game called a "seven point tiebreak." Points are counted using ordinary numbering. The set is decided by the player who wins at least seven points in the tiebreak but also has two points more than his opponent. For example, if the score is 6 points to 5 points and the player with 6 points wins the next point, he wins the tiebreak and the set. If the player with 5 points wins the point, the tiebreak continues and cannot be won on the next point, since no player will be two points better than his opponent. Since only one more game is played to determine the winner of the set, the score of the set is always 7-6 (or 6-7). Sometimes the tiebreak points are also included, for example 7-6 (7-4). Another way of listing the score of the tiebreak is to just list the loser's points. For example, if the score is listed as 7-6 (8), the tiebreak score was 10-8 (since 8 is the loser's points, and the winner must win by two points).

The player who would normally be serving after 6-6 is the one to serve first in the tiebreak, and the tiebreak is considered a service game for this player. The server begins his service from the deuce court and serves one point. After the first point, the serve changes to the first server's opponent. Each player then serves two consecutive points for the remainder of the tiebreak. Further, the first of each two-point service starts from the server's advantage court and ends in the deuce court. After every six points, the players switch ends of the court. At the end of the tiebreak, the players switch ends of the court again, since the set score is always odd (13 games).

What is Tiebreak??

Whenever a set leveled at 6 games all, a 7 point tiebreak with 2 points apart will be used. The 1st server serve the 1st point and than every 2 points by rotate. Every 6 points change side.
This is to shorten the time used instead of using long set. But in some tournaments, the final set is still using long set (2 games apart).

In mid 60s, American Charlie Passaral vs Pancho Conzalez finished the match in 102 games (6-3, 12-14, 2-6, 6-3, 26-24) for 8 hours plus & made the history of the longest single match, so, it would not happen again when Tiebreak is used in the late 60s..