Racing people call it “training on”. And it's precisely what's not happening to Andy Murray. Training on is the process of turning promise into achievement, turning precocity into maturity. You are no longer eye-catching, you are the one everybody was already looking at.

And in horses and people both, the process is as much about mood and nature and temperament as about physique and experience. A horse that trains on changes its view of the world, settles down, becomes more assured, is more relaxed about the training process and more effective at the business of producing his best on the track.

That's not anthropomorphism, that's training.

This is what is not going on with Murray. He turns 21 on Thursday. He should be fast approaching his peak; he seems to be returning to his foothills. Now, I know that 21 is absurdly young, as the world goes. I doubt if I began the process of training on myself until I was past 30. But then, I was not an elite athlete.

A champion has to mature young. You can train on as a human being at whatever stage of life that seems right, but you can only train on as an athlete while you still have an athlete's body. By the time I was training on, most athletes are retiring.

So the clock ticks, while Murray keeps losing to opponents ranked lower than him. He gets mind-locked into the tactic of keeping the ball in play waiting for a mistake; inappropriate in one so extravagantly talented. When that doesn't work, he plays a drop shot every time the ball comes near him, and gets furious when it doesn't work.

He has a vast retinue. He sacked Brad Gilbert as his coach, even though he was supplied by the Lawn Tennis Association at vast expense; well, what can a man who has coached Andre Agassi teach Murray about tennis? Not only is Murray rather young to produce an autobiography, his book is apparently to be called Hitting Back. Against whom? Who has ever done him wrong?

He has acquired the demeanour not of a champion in waiting, but of a gap-year kid with a grudge against the world. He is behaving like someone who has had it too easy, has too many sycophants, has been made too much of, has taken things too easy. He is behaving, in short, like the classic pampered English tennis prospect: able to enjoy the fruits of success without needing any actual success. Murray is a Scot, so that is meant to sting. Murray needs to train on, kick into phase two of his career, and now would be a good time to start.

Imbalance is shown again

Free to those who can afford it, very expensive to those who can't. Words from Withnail & I; perhaps the FA should adopt them as a motto, for that has been the way of the Premier League since it began. Manchester United have been great this season, and Cristiano Ronaldo remarkable, but what a dispiriting denouement to the season: a succession of big refereeing decisions going Manchester United's way, as always.

Steve Bennett reminded me of Russell Brand pretending to crawl to the Queen at the Royal Variety Performance. Call it unconscious bias: he didn't give a penalty when Rio Ferdinand handballed in the box; he did when Emmerson Boyce caught Wayne Rooney at the other end; he didn't send off Paul Scholes for a second bookable offence.

Thus the balance of the afternoon's entertainment shifted irrevocably. And there seems to be a question worth asking: does parity of competition actually matter? Does it matter that four clubs relentlessly expand their overseas support-base while the rest cling desperately to what they have?

The answer is star-worship. Star names, whether of clubs or individuals, are all that matter in modern football. But it is essential to have the right number of the drab and the nameless, or there is no dull, dark background from which the stars can twinkle. Bennett was just doing his duty to the system.

King always up for battle

Mary King had a horrid fall at Badminton last week, tipping out sideways at a terrifying obstacle. That worries her - and terrifies her - about as much as you and I worry about tripping over the doormat. Now she has been selected for the Great Britain eventing team for the Olympic Games this summer.

It will be her fifth Games. She will be 47. She is one of the most consistent performers in British sport, possibly the bravest and probably the maddest. You are entitled to lose your nerve after breaking your neck in a fall, but not King. She rode leading events when five months pregnant.

You wouldn't know she was mad to meet her. She is delightful, charming, self-deprecating, unassuming, approachable. On one occasion she had agreed to speak to me after her dressage test. As we met the heavens opened. She was far too well brought up to consider ending the conversation; it was me who told her to get her horse in the stable and rugged up and to worry about me second.

She is a fabulous rider with a deep thirst for competition and, after all these years, utterly unsated. If there is a more remarkable athlete in this country, I'd like to be introduced.

England's Ashes journey begins

It's time to get excited about the Ashes. Not in a “wishing your life away” sense; rather, it is time for the England cricket team to begin their ascent towards a peak. Four years ago, England took on New Zealand and beat them 3-0. It was a crucial stage on the ascent to the great Ashes summer of 2005.

Now it's New Zealand again. Not the sexiest Test series in the world, it must be said. So look for certain signs. Look for ruthlessness. This is not an attractive trait, it is true, but compassion is inappropriate. England's first stage must be a voracious gourmandising on their opponents' uncertainties.

England must conclude this series with an enhanced sense of self-worth. The second stage must be a great mano a mano contest with South Africa. But first, the establishment of certainties.

Meaningless milestones in meaningless games

Has anyone worked out what the cricket match between England Lions and the New Zealanders was for? It wasn't exactly a ferocious seeking-out of English talent. Rather, it was a gentle warm-up for the New Zealand players, a game devoid of intensity and meaning.

All English cricket - perhaps all English sport - was summed up in Michael Carberry, who leapt in the air to celebrate his century and was carried off with cramp. He went back yesterday to add eight runs. Self-satisfaction as a meaningless milestone in meaningless circumstances was overvalued to the point of self-destruction. I wonder what they said in Australia.