Directly before Ronnie O'Sullivan polished off Ali Carter in the final session of the snooker World Championship, a man called Mark Roberts seized a brief window of opportunity to bound over the advertising hoarding, step out of some pre-loosened clothing and offer a tightly packed arena and the watching nation the benefit of his bareness.

Four years ago the same streaker did a similar thing in the same place when O'Sullivan was playing Graeme Dott. All the evidence suggests that Roberts is on a one-man mission to make freelance nudity as much a part of the furniture at the World Championship as chairs and Steve Davis. Presumably the streaker won't rest until Velcro-fastened over-garments are on sale in the Crucible lobby, alongside the Ray Reardon-endorsed cue tips and the Stephen Hendry mugs.

It can't be easy to become a serial streaker in the same venue. The security people are going to cotton on to you eventually. Or is no one keeping an eye out for known exhibitionists in the area, the way they do for football hooligans? Clearly no one on the door recognised Roberts this time. Not by his face, anyway.

At the same time, does the legendary Sheffield venue genuinely lend itself to streaking? Roberts ought to know, having streaked at sporting events as far flung as Royal Ascot, the Olympic Stadium in Seville and the 2004 Super Bowl in Houston - which takes some guts. Those American policemen are armed, you know.

On the one hand the Crucible is snooker's theatre of dreams, providing the potential nudist with a focus as intense as any in sport. On the other hand it's a strictly confined space that provides little in the way of a platform for the broader, naked gesture and also offers no bracing, outdoors exposure whatsoever - unless you begin from the car park.

Roberts didn't exactly lessen one's unease by going almost straight away to hide under the table. True, this loaned a bonus, Michael Crawford-style slapstick element to the relief effort by the staff responsible for dragging him out. Yet, either this was an unusually conflicted streak, or something inherently contradictory was going on here.

Talk to Hazel Irvine about it, though. Receiving the full-frontal impact, while innocently going about her business of handing over to the commentary team, the BBC's admirably calm presenter produced a moment of ad-lib genius. “That reminds me,” she said. “Willie Thorne is in the commentary box.” Whole careers teeter on these moments and if Irvine hadn't already amply justified her selection over the course of the World Championship, that split-second response under pressure would have been enough to guarantee her lasting status as a safe pair of hands.

You could argue that the invited and clothed guests at the Crucible were more startling, in their own way, than the uninvited, unclothed ones. In the final session alone the commentary team had cause to introduce us to a poker player (Dave “The Devilfish” Ulliott), a retired cricket umpire (Dickie Bird) and a man who suspends cows in formaldehyde. “That's the artist Damien Hirst,” Dennis Taylor smoothly explained. “Loves his snooker,” he added.

Then there was Duncan Preston, the actor. “Loves his snooker,” Taylor added, again. We were getting the picture.

Everyone here who was famous loved their snooker. One quietly longed for the cameras to pick up a member of Girls Aloud, slack-jawed with uncomprehending boredom, leading Taylor to say: “Can't stand the game. Here entirely on sufferance.”

But it was never going to happen. On snooker's big night, everyone is engrossed. Everyone bar the flashers.