On hard courts in the US this year, Roger Federer introduced a new technique that has never appeared on a professional tennis court.

At the age of 34, father of four children, Federer suddenly regained his youth.

`Sneaky Attack By Roger` is the name that Federer’s team gave to this new shot.

Federer entered the US Open semi-finals without losing a set.

The first time Federer performed SABR was in Cincinnati, against Kevin Anderson.

SABR delivers immediate results.

The advantages of SABR are: surprising, confusing the opponent, putting pressure on the first shot after serving.

But this trick is not always effective, like the video below about the match between Federer and Leonardo Mayer in the first round of the US Open.

Federer’s SABR shot

`When I practice, I often use this move, as a joke. Then I try again, continuously and it doesn’t seem difficult to do,` Federer shared.

Coach Stefan Edberg encouraged Federer to try this move in real competition.

No one questioned the martial quality of this move, even though there was clearly movement and distraction before the opponent served the ball.

But recently, legendary Boris Becker, Djokovic’s coach, criticized the world number two player.

Becker was not satisfied with the SABR move.

Federer was once considered conservative, saying no to changing to a large racket or not accepting an immediate `challenge` of the referee’s decision.

Federer is flourishing at the US Open without losing a set until the semi-finals.