Wimbledon chamapion Rafael Nadal's game, like many other top-level sportsmen, is riddled with quirks and obsessive-compulsive traits.
According to The Sun, the most obvious trait is that he constantly arranges his water bottles.
He is determined that they must sit in an exact position between his feet in the break from play at each change of ends.
If the bottles are facing the wrong way - or not in line with each other - he fiddles until they are just right.
He then takes a few sips from each.
Female viewers will also have noticed that the star also adjusts his underwear each time he serves.
And watch him closely as he walks off court.
You will see that he makes sure never to step on the white lines - and even adjusts his stride to avoid them.
Also, he always ensures his sweatbands are in the correct position on his wrists before he serves or receives a serve.