He can run a mile in four minutes and 50 seconds and it doesn't take him long to get through his stockpile of 40 episodes of Countdown.

Now Liam Walsh is plotting to do a number on the Russian man of mystery, Andrey Klimov, on Saturday, when the pair do battle for the right to fight for the IBF super-featherweight world title.

The final eliminator is top of Frank Warren's bill in Harrow, and justifiably so: it's the biggest challenge of Walsh's career, putting his own 20-0 unbeaten record up against Klimov's 19 wins and two defeats.

It will different on Saturday, but yesterday, as he sat in the Kickstop Gym in Norwich, Walsh looked as far away from the biggest moment in his career as you could imagine. Save for some last-minute glitches over a medical document, Walsh was laid back; relaxation personified as he shared media duties with twin Ryan, who, seven days later, sees his career hit a new peak with a European title shot.

There is a deeply cerebral side of Liam Walsh – the one that loves the Countdown puzzles and conundrums, the one who talks deeply and meaningfully about the tragedy following the death of Mike Towell after a fight last week, the one who protects his right to a private life out of the ring.

If that sounds unusual for a fighter, then perhaps the contradiction will come on Saturday night when a different Liam Walsh steps into the ring.

The steely look in his eyes gives it away. 'When that first bell goes, it becomes serious, serious business,' says the Cromer man.

Five years ago last weekend, Walsh was involved in a battle royal with Paul Appleby, hitting the canvas for the first and only time in his pro career, but sweeping around a huge section of boxing learning curve.

It has taken him to a European title and a British title and now it takes him closer to a possible world title.

'This is my biggest challenge, no doubt about that,' says Walsh, 30. 'I don't know much about him – I don't think anyone does. I have had reporters ringing me asking me what I know about him.

'I have always looked into my opponents in detail to find any edge I can get, but there is nothing on this guy.

'I am not even sure that is his real name - he is from Klimovsk in Russia, so I think they have just called him that. He seems to be a very private person, like myself. Boxing is our job, our working life – outside of it I am private too.

'I am more than happy to just sit at home and watch Countdown. People can call me boring, and I think I am – and old before my time. I love Scrabble and I love chess. When I got back from training in Tenerife I had 40-odd episodes of Countdown to watch and I've got through them all.'

What is unlikely to be anywhere near boring is Saturday night's fight. Walsh has made a commanding rise to the top of his profession. Klimov, at 34, has just one more fight on his record. His last was an attempt at the then vacant IBF world super-featherweight title when he lost on points to Jose Pedraza.

'He had his nose broken against in the fifth round and it went to points – his face was swollen, his forehead and eyes, blood everywhere, and he got on with it, didn't whinge,' said Walsh.

Walsh's answer to the Klimov conundrum will be revealed on Saturday night.