By Sophie Brown BBC Sport Online

Timmy Murphy is the not the first jockey with a drink problem and will probably not be the last.

But the drunken behaviour that has earned the Irishman a six-month stretch behind bars threatens to halt a career that had just entered the big time.

The 27-year-old had been enjoying his best season to date, notching up 98 winners in 2001/2.

And had it not been for the break he took from the saddle after being charged with assault, he would doubtless have passed the century mark.

Racing is in Murphy's blood.

He worked weekends for Gold Cup-winning trainer Noel Chance while still at school and his father was a leading Irish amateur rider.

Riding for Chance, Michael Hourigan and Mick Halford, Murphy became the Irish amateur champion.

He then took the well-trodden path to England, where he rode for Kim Bailey after turning professional in 1996.

But it was Murphy's second stint as stable jockey for Paul Nicholls that saw him become one of the leading jump jockeys around.

Nicholls was one of the top three trainers last season, sending plenty of winners Murphy's way.

They included Armaturk, who won the Martell Maghull Novices' Chase the week before Murphy's ill-fated trip to Japan.

He also had a couple of big wins on old warrior See More Business and enjoyed Cheltenham Festival success with Terao in the Mildmay of Flete.

At Murphy's trial, Michael Caulfield, chief executive of the Jockeys' Association, said jockeys turned to drink to escape.

"It's a very stressful lifestyle with danger and stress," said Caulfield. "It's the most intense of all professional sports."

The battle with weight, the incessant travelling and the ever-present threat of serious injury drives some riders to the bottle.

Terry Biddlecombe, legendary champion of yesteryear, and last season's Champion Hurdle winner Dean Gallagher are among those who have battled with booze.

Murphy himself had two previous convictions for drink-driving.