Back in the early 1990s, Boris Becker lived secretly in his sister's house in Munich and Andre Agassi wore a memorably loud hairpiece. Both were permanent residents of tennis's Top 10.
Becker possessed one of the most powerful serves in tennis. His 1985 Wimbledon victory, achieved as a 17-year old, was said to have ushered in the era of 'power tennis'. Finesse merchants like John McEnroe would rule the roost no more.
Andre Agassi arrived in the late '80s as a counterpoint to that. His serve wasn't intimidating but he was renowned as the best returner of the serve in the game.
In head-to-heads, the big server usually holds the advantage. Except that Agassi finished his career with a formidable head-to-head record against Backer. This he has subsequently credited to the power of stunning observation.
After losing the first three matches against the German, Agassi spotted something very minute but ultimately rather important.
Whenever 'Boom Boom' was winding up to serve - you might remember he had a distinctive rocking motion before unleashing his shot - his tongue used to jut out of his mouth.
Amazingly, Agassi noticed that whenever Becker's tongue jutted out between the middle of lips, he would lash his serve down the line or into the body of his opponent. Whenever his tongue hung out of the corner of his mouth, he was going down the line.
The most impressive thing is not even that Agassi noticed this.
In possession of this game-winning information, Agassi's primary concern became not alerting Becker to the fact he could read his serve so easily.
Crucially, he chose not to exploit his advantage every time. If he returned every serve then Becker, or his coach, would realise something was amiss.
He would casually allow Becker's serve to whizz by him for much of the match and would instead pick his moments to exploit Becker's 'tell'.
I had to resist the temptation of reading his serve for the majority of the match and choose the moments when I was going to use that information on a given point to execute a shot that would allow me to break the match open.
I didn't have a problem breaking his serve. I had a problem hiding the fact that I could break his serve at will because I just didn't want him to keep that tongue in his mouth. I wanted it to keep coming out.
Watch Agassi below:
This! Andre Agassi. What an observer. Pure genius. ✌️?? pic.twitter.com/QUFtdJddcR
— Ayushmann Khurrana (@ayushmannk) January 19, 2017
Clearly, Pete Sampras's tongue, which often hung out of his mouth on court, didn't give any clue to where his serve was going. Sampras had a career record of 20-14 against Agassi.
