Sam Twiston-Davies is to replace Daryl Jacob as stable jockey to champion trainer Paul Nicholls next season.
Announcing the news in his Betfair column, Somerset trainer Nicholls said there had been "no falling out" with Jacob, who is currently sidelined with an injury suffered in a freak accident at the Cheltenham Festival.
Having made his name riding for this father Nigel at their Naunton base in Gloucestershire, Twiston-Davies has partnered a number of high-profile horses for Somerset-based Nicholls in recent months, including Big Buck's and Tidal Bay.
The Ditcheat trainer said the ride on King George VI winner Silviniaco Conti would remain with Noel Fehily, and that Twiston-Davies would continue to ride his father's Champion Hurdle third The New One.
Nicholls said: "Sam Twiston-Davies will be the number one stable jockey.
"He will have the pick of our team, with the exception that Noel (Fehily) keeps the ride on Silviniaco Conti. But it is also a two-way street as regards the top horses, and we have agreed that Sam will continue to partner The New One for his father for next season.
"I told Daryl (Jacob) of the decision on Friday, when I also offered him the number two job. He then took the weekend to think it through, and he came back to me today to say that he would rather go freelance.
"But I have to stress that there has been no falling out, and Daryl will continue to ride out and school a couple of times a week here next season and ride too."