A former NHS call centre worker has won the best show prize at the prestigious Edinburgh Comedy Awards.

Jordan Brookes’ experimental, convention-busting show I’ve Got Nothing claimed the £10,000 prize on Saturday in what was the most ethnically diverse and gender-balanced line-up since the awards began 38 years ago.

“They just went with the white dude in the end,” Brookes, 33, joked as he accepted his award from the first ever winner, Stephen Fry.

Born on Merseyside, Brookes grew up in Surrey and comes from “a vaguely entertainment background”. His grandfather worked for the BBC and produced “the worst soap in history, Triangle, until they paid him off”.

The winning show is a sort of cat-and-mouse game with the audience and involves several false endings. “It works more than it doesn’t, which is a surprise,” Brookes said. “It’s a constant battle. If the audience aren’t engaging with it or are a bit reserved, then I have to change things, move things round, but it’s fun – keeps me on my toes.”

Brookes said about 40 minutes of the hour-long show was scripted, and the rest improvised. “I wanted to do something a bit freeform, and it allows me to go off road and have fun with it.”

He was at pains to say, however, that the running gag in the show about seducing his mother was entirely fictional. Then, clutching his award, he quipped: “This should help, though.”

The 10-member judging panel – which included Nosheen Iqbal of the Observer – saw 759 shows, a record number for the award. The nine shows nominated for best show and eight for best newcomer included gag-based standup, autobiographical works, experimentalism and surreal, sketch and prop comedy.

The best newcomer award went to New Yorker Catherine Cohen, 28, for The Twist...? She’s Gorgeous, a show with songs about her dating history and the male gaze. The Scottish actor Alan Cumming is her mentor, and she performs regularly at his club in New York, where he lives.

Catherine Cohen performs The Twist ...? She’s Gorgeous at the Pleasance Courtyard. Photograph: Murdo MacLeod/for the Guardian

The panel prize - an award given by the judges to an individual who embodies the spirit of the Fringe - went to Jessica Brough, who set up the Fringe of Colour initiative, which aims to give free tickets to people of colour to see Fringe shows by black and minority ethnic (BAME) performers.

The two main lists included the first black British female comics to be recognised: London Hughes (nominated for best show) and Sophie Duker (on the newcomer list). The newcomer list had 63% BAME ethnic representation, and the gender split was almost equal for the first time over both lists.

Nica Burns, the awards’ director, said: “This was an extraordinary, record- breaking year with a 45%-55% women/men gender balance. It was the most diverse group of nominees in the history of the awards with the widest range of genres. The future of comedy looks fantastic, and it is here.”