Tennis can be the most solitary of pursuits. First comes the countless hours spent pounding balls in practice with little more than thoughts for company - the net separating you from your coach or practice partner as surely as it does from the rest of the world.
And where does this all lead? In the end, come match day, you have to head out there on court, one player - alone - against another.
So maybe that's why, more than any other sport, tennis has long been a place where family comes first as well. When you are alone, there is no better place to turn. Look left of centre court at any tournament in the world and you will see, gathered in the stands and back rooms, fathers and mothers, brothers and sisters. It's as though players - faced with the solitude of the craft - react by surrounding themselves with familial security as soon as the last ball has bounced.
This week's Watsons Water Champions Challenge was a case in point. Maria Sharapova only had to glance a little to the left to see her father, Yuri, watching her every move. Kim Clijsters could be seen laughing with her mother, Els, while she signed autographs. And Elena Dementieva could often be caught on the outside courts, grinding her way through practice sessions with mother Vera close at hand.
For those three players - with a combined 25-odd years on the WTA Tour - the routine has by now been firmly established. They know these are people they can rely upon, opinions they can trust, shoulders they can lean on.
For those starting out on the WTA Tour, though, things are a little different. The families of youngsters Caroline Wozniacki and Nicole Vaidisova are still very much learning what it means to have a family member involved in the tennis circus. And as the annals of tennis history have shown, there is a very fine line between influence and interference.