Dara O Briain on how Mock the Week has mellowed

"Then there were the angry young man years, when it was very bolshy. Now it's much more reflective. It may be we're all a little bit older. Or maybe it's because Frankie [Boyle] has gone. But there's not the same emphasis on savage one-liners. It's much more of a messing-around kind of show, which for me is a lot more fun. We're in that third phase."

So did it feel like it had become Frankie Boyle's show?

"Frankie would distil the discussion into a brilliantly punchy killer line. Putting comedians together is like a jigsaw. Some are open-ended: they say something to add to the discussion and move it along, riffing on it. Frankie would be more: bang! That's the end of that. That's the last word on that topic. That was his genius – and it was perfectly suited for the editing of this kind of show - but it did breed an atmosphere where everyone had to get in there as quickly as possible. We became a bit of a bear pit. People who do it now don't find that."

O Briain observed that Mock the Week's policy of booking only stand-up comics as guests may have contributed to its harsh tone: "Mock the Week is unusual in that only stand-ups do it. Most panel shows give themselves the luxury of a celebrity booking – they offer a breather because they're not expected to come out with jokes and they can say things the comedians then jump onto. That helps. We, crazily, have seven comics on every show! All of them are professionally obliged to do their own jokes. You're meshing seven different comedians all trying to be funny. On Would I Lie to You there are maybe four. Have I Got News for You: three or four. 8 out of 10 Cats: two captains and maybe one or two others. Seven is just ridiculous!"

As host, O Briain has sometimes felt the need to help less experienced guests along. "Seann Walsh is a very talented comic and he's never done badly on the show, but he did say once that he was on and he'd suddenly thought "Oh my god, I'm on the show!" and then he didn't say anything for a few minutes. It can move so quickly past people that if you haven't done it several times before, it's bewildering. It was like fingers on buzzers. It's less of an issue now. When you're bringing new people on you have to carve them a bit of space."

So was it a conscious move to make it less gladiatorial, or was it just that Frankie Boyle left? "Actually, it was Frankie and Russell Howard. Russell was similar. It wasn't just that Frankie's comedy was dark: he and Russell would bang it across to each other and the other four, and me, would have to find windows within that. When Chris Addison came in, his natural thing is to pick up things that have been said and run with them, to be listening as much as talking and look for off-the-cuff things – that's my instinct too. That's why it's shifted in that direction."

Changing the feel of the show might account for some of its longevity – but for O Briain, as a maths and physics graduate and self-confessed numbers nerd, a superstitious milestone like the hundredth episode doesn't mean much.

"Being a numbers man means they're all the same for me," he told Radio Times. "It's like when there was a whole debate about whether David Beckham should be allowed to join the club of people who had 100 caps for England. I remember pointing out that he was already in the club of people who had 99 caps, so it was relatively moot whether he got another one. As if somehow now he was on a par with Billy Wright and Bobby Moore – he already is!

"I'm not one of those numbers nerds who says no, that's not really the millennium. I'd celebrate 100 episodes if by chance it fell on the last episode of the series. I could combine the parties."

Mock the Week series 11 continues on Thursday nights on BBC2.