Hewitt's gamble

Hewitt has got rid of his coach Darren Cahill

BBC tennis correspondent Iain Carter wonders whether Lleyton Hewitt was right to change his coach when everything was going so well on court.

Rather like that age old tip 'never tie your shoelaces in a swing door', I've always attached great value to the maxim 'if it ain't broke, don't fix it'.

Clearly this kind of logic doesn't stretch as far as the upper echelons of world tennis, with the planet's newly crowned number one, Lleyton Hewitt, ending the year by splitting with his coach, Darren Cahill.

They had struck up one of the most successful player/coach relationships imaginable.

Falling out

It began with Hewitt a scrawny teenager ranked outside the top 100, and ended with a 20-year-old on top of the world with the US Open title in his pocket.

It never ceases to amaze me how a well of common sense can run dry when personal differences are allowed to surface.

It seems Hewitt's parents, Glynn and Cherilyn, had fallen out with Cahill in the summer, which sowed the seeds of the split.

Stoltenberg has little coaching experience

When it came to renegotiating the coach's contract, accord broke down over whether Cahill would be able to travel the tennis world with his young family.

As a consequence, the contract wasn't renewed and Hewitt has turned to a former Wimbledon semi-finalist, but rookie coach, Jason Stoltenberg.

Given the unrivalled progress made by Hewitt, it's an extraordinary turn of events, though not unprecedented.

Greg Rusedski - and let's face it, he knows a thing or two about the hiring and firing game - showed Brian Teacher the door within days of reaching the US Open final.

It's assumed money was the issue on that occasion, but again it defied all logic.

Rusedski, meanwhile, is once again on the search for a new mentor.

Glorified ball boys

Then there's Pete Sampras, another to have visited the coaching carousel in recent weeks.

His decision to part with Paul Annacone makes absolute sense.

The seven-time Wimbledon champion endured his worst year for more than a decade in 2001.

He ended it in serious need of fresh impetus which his new man, Tom Gullikson (twin brother of Tim Gullikson, Sampras' former coach who died of brain cancer in 1996), is well qualified to provide.

Tim Henman recently told me he's "so excited" by what he's hearing from his new mentor Larry Stefanki and believes 2002 will vindicate his appointment.

But others claim the role of a coach is over-rated and most are glorified ball boys for practice sessions.

That massively undervalues their role, which first and foremost is to create a happy and productive environment for their player.

Cahill certainly did that for Hewitt.

And like whoever succeeds Sir Alex Ferguson in the soon to be revolving door at Old Trafford, Stoltenberg has the toughest of acts to follow.