His numbers look more extraordinary when compared with the top three international ODI run-scorers. Sachin Tendulkar's ratio is 3.11, Ricky Ponting's 3.26 and Kumar Sangakkara's 3.27.
The world's current top three-ranked ODI batsmen have better ratios - AB de Villiers (2.77), Virat Kohli (2.63) and Hashim Amla (2.26) - but it's understandable why captain Brendon McCullum said he wouldn't swap Williamson for anyone - the 24-year-old is ranked sixth.
Batting is notorious for its fickle nature. Millimetres can differentiate brilliance from ineptitude and sustained form is the exception rather than the rule.
Williamson's role as a safety net at No 3 is pivotal to New Zealand's World Cup chances. He has the mental fortitude to enter from the second ball and compile his runs without freezing under pressure.
A census of statistics could be generated as his feats track in parallel with New Zealand's current form. However, it's also important to understand what makes him tick.
Williamson is inscrutably modest and selfless. He speaks in the first person about as often as he hits in the air. Get him on to the value of his team-mates and the respect flows as smoothly as his stance coiling into a back-foot drive.
Williamson is embracing the tournament and the New Zealand cricketing public are embracing him.
"You get the odd person coming up to greet you, and it's cool," he says. "The amount of cricket and the way it's been played [over summer] has created a lot of interest. That's ultimately what it's about - growing the game and making it better for everybody."
At last week's ODI against Pakistan in Napier, Williamson punched two runs off the back foot through the covers and a child in the main stand tapped his father on the shoulder to demonstrate a mimicry. That's Williamson's impact on the next generation. They think this is how New Zealand cricket has always operated. Their mums and dads know better.
"I'd have thought they'd be practising a few more of Brendon's strokes," Williamson quips. "I watch Brendon and try to do what he's doing. There are certainly better players to watch than me."
There will be dissenters to that statement. Williamson has reignited a retro strokeplay trend without any premeditated gimmicks.
Like the best sub-continental batsmen, he seldom over-hits. It's more about the timing. Even when he advances down the wicket, he tends to hold the shape of his shots rather than taking the easier route of clearing the front leg and blasting over cover. Williamson's form has earned widespread attention.
"He's the key around which their whole batting unit revolves," Indian great Rahul Dravid told cricinfo. "They rely on him to bat through the middle around a lot of their stroke players like McCullum, Taylor, [Corey] Anderson and [Martin] Guptill.
"He's also a brilliant player of spin, and creative as well. He's actually a good, classical batsman who's able to find the gaps, hits good cricketing shots, and has great consistency as well."
"It'd be lovely to hear what has changed in his game or his mindset [over] the last year when his game has gone to a new level," former South Africa captain Graeme Smith added. "I think he's provided the stability which New Zealand have always lacked. I think most teams will look at him and say, 'how can we get him out early'?"
One way which appears futile is to sledge. The proof to that hypothesis will be when he cops inevitable abuse as part of Australia's modus operandi on February 28 at Eden Park, but Williamson's been unflappable to date.
"I haven't endured a huge amount [of sledging]," Williamson says. "Some individuals try to pursue that more than others but, in general, it doesn't tend to happen much. In the last wee while [against Pakistan and Sri Lanka] the game's been played competitively but in a good spirit with a lot of respect."
Speak to anyone about Williamson and 'respect' recurs in conversation.
Former Bay of Plenty Cricket boss David Johnston has been a mentor in Williamson's career which began as a Tauranga prodigy. He says Williamson's approach hasn't wavered from respect for the next ball and respect for the opposition.
"From the time he was five until now, everyone admired the way he conducted himself," Johnston says. "He doesn't give many opportunities to be baited. Take the Sri Lankan series. When one of the opposition scored a century he was one of the first to shake hands. It doesn't matter if it's the opposition's baggage man or their best player, Kane's affable.
"He takes a balanced approach to life into cricket. He doesn't believe in form, he just believes in getting better. It's not defined solely by scoring runs. People might misjudge it for being cold and calculating but Kane's as passionate as anybody about winning. It's just his approach is one of level-headedness and maturity. He's good at problem-solving."
With that statement, Johnston might have tapped into the Williamson secret. Cricket, while important, is not the be-all and end-all. He has a phenomenal record because his lifestyle, with a tight family and sensible investments, like a house at Mount Maunganui, is balanced.
Williamson went home in the three-day window between the Pakistan series and assembled for the World Cup build-up yesterday. He headed for the sand where he was pleased not to get recruited for any beach cricket on what he joked was a "dodgy" Mt Maunganui track.
Williamson also doesn't want to get distracted by good opposition.
"The teams which play with freedom and less baggage generally progress [at the World Cup]. That's the challenge for us.
"The World Cup's about playing the best. Sometimes you're in the field watching them perform their art and it can be a bit annoying because you want to dismiss them, but you can learn a lot as well."
