Cambridge unicycling juggler breaks Guinness World Record using artificial intelligence

A unicycling Cambridge University student has achieved a juggling world record, having honed his skills with performance analysis software that he developed himself.

Engineering PhD student James Cozens broke the Guinness World Record for "most objects juggled while riding a unicycle" - juggling seven balls for 16.77 seconds at Cambridge's Selwyn College.

Participants must juggle for a minimum of 10 seconds for a successful attempt.

The 23-year-old said that his academic background helped him to improve his juggling technique by developing his own performance analysis software to help jugglers.

His software shows tracking, visualisation and simulation of "siteswap" routines - with siteswaps being sequences of numbers representing the relative duration of throws in a juggling pattern.

"I think the technical approach has really helped because having this academic background means I can develop the software and see where my technique needs to improve, increase my efficiency, and it's been a lot of fun," said Mr Cozens from Gerrards Cross in Buckinghamshire.

His undergraduate degree was in information and computer engineering, and he said that "a lot of the algorithms and techniques learnt in that were used directly in the software".

"My PhD is in statistical signal processing, machine learning, so basically artificial intelligence," he said.

"One side is in generative music, the other is multi-object tracking, which you can imagine is very useful for this kind of juggling software."

He said the software helped him reach the standard needed to achieve the record.

James Cozens with his certificate from the Guinness Book of World Records Credit: PA Images

"The whole purpose of the software is to provide a juggling analysis," said Mr Cozens.

"It provides information like technical analysis, offers technical advice and visualisation of the routines you're performing.

"So for me anyway it helped a lot trying to understand my efficiency as a juggler."

He took up juggling during his first-year exams "just as a stress relief and also as a great break from the academic grind".

"Then Covid happened, there was a bit more free time and a lot of time to learn new tricks and so on, just a lot of fun," he said.

"I just carried on juggling, juggling, juggling.

"It was just a lot of fun, I had new ambitions, the record was there, it seemed like a fun thing to try."

The record was achieved at his college, Selwyn, with two timekeepers, two independent witnesses and the feat verified via the Guinness World Records website.

"It took many attempts to get to it," said Mr Cozens. "It's a very unstable system - you have going on juggling at the same time, but the more you practise it the more it slowly builds up and up.

"I spend an hour or so practising a day just as a break from the academic grind. I think it's a really fun way to get away from pure academics.

"It takes your mind off everything; it's a fun thing to do."

He said he practises around Selwyn College, occasionally around the front of King's College and at Jesus Green, which he described as a "nice picturesque area".

"I would recommend juggling as a fantastic fun activity to try; it's also great cardio and stress relief," he said.

Mr Cozens' software, originally a hobby project, has been integrated into his PhD work and was first tested at the 2022 European Juggling Convention.

He hopes the software will help other jugglers to improve their technical efficiency, and to help adjudicators evaluate performances during competitions.

"This is increasingly important, given that those in the juggling industry are hopeful that the sport can make its Olympic debut in the next couple of decades," said Mr Cozens.

He said that "limited software" had existed for juggling tracking "due to the complexity and variability of conditions".


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