Ruby Walsh's success on Black Hercules for trainer Willie Mullins in the Novices' Chase has made him the first post-war jockey to win 50 races at the famous Cheltenham Festival.

In 1998, Mullins and and an 18-year-old Walsh combined for the first time to score at Cheltenham when Alexander Banquet won the Champion Bumper.

Since then Walsh has been unstoppable at Britain's biggest jumps meeting of the year, winning big race after big race for trainers like Mullins and Paul Nicholls to become the most successful jockey in its history.

The landmark on Black Hercules in the Novices' Chase and was followed by two more on Vautour in the Ryanair Chase and Limini in the Mares' Novices' Hurdle to take his tally for the week to seven.

Going into the final day on Friday (Saturday AEDT) Mullins is one short of the record eight Cheltenham winners he trained a year ago.

"He's the best jockey I've ever had riding for me," Mullins said.

"From the time I saw him as a 7lb claimer, he was different gravy and he still is. I first saw him riding a winner at Gowran Park and was impressed.

"We couldn't imagine that this would all happen all these years later, but I did know that Ruby was going to be a top, top jockey.

"He just oozes class and he's always in the right place at the right time in a race."

Walsh deflected praise to the trainer.

"It's different for me nowadays," he said.

"I've become very much part of the team and we all work for a genius."