But as he's proved over close to 500 international matches, there's nothing wrong with blending strong technique, immense concentration, consistent application of his skills and making the very most of natural abilities.
"I'm probably batting as well as I have ever batted, certainly from a confidence and technical point of view," Kallis said this week.
"The last couple of years have been really good and I've scored quite quickly as well because I've got into good positions."
But numbers aren't his thing.
"I must admit I'm terrible when it comes to numbers. I don't tend to look at them. Once you start focusing on your own game you lose sight of what the team needs in certain situations.
"I've always said if you play the game and try to win for your country, numbers take care of themselves."
Just as Sachin Tendulkar marches on in search of the contrived 100th international century, 23 years after his first match for India, so Kallis isn't going anywhere soon.
These are men for whom the game matters. They're still in love with it after all those years, still pushing the boundaries.
"I'm probably not as excited [about touring] as when I was 18 or 19 but I still love playing. I enjoy the challenge of a new tour and hopefully I can contribute with the bat and ball and off the field in a big way."
Kallis' first five tests produced 57 runs. Next time out, at Melbourne in December 1997, his 101 effectively saved the test against Australia, staving off Glenn McGrath, Shane Warne and co on a worn pitch.
Since then he's been remorseless. Only Tendulkar has scored more than his 41 test hundreds; he's fourth overall on for test runs.
Consider a couple of periods. Kallis hit five centuries in the space of eight innings between December 2003 and the following March, the last of which was in Hamilton.
His past 33 innings have produced 11 centuries, most recently 224 against Sri Lanka at his home ground, Cape Town.
Against New Zealand, his test average of 67.8 exceeds his overall figure by about 10 runs an innings.
His last two test innings against New Zealand ended in three figures, at Johannesburg and Centurion five years ago. He first faced New Zealand at the 1996 World Cup in Faisalabad.
His lively medium pace has been a key cog in South Africa's bowling attack as third or fourth seamer, and throw in his glue-like hands, which have snared 176 catches for his country and his value in terms of contribution and balancing the team are evident.
If there has been a criticism of Kallis it is that at times his batting has seemed out of sync with the requirements of the situation. That is, his mind has been more on himself than the team.
Still, 17 years on, a South African test side without Kallis still looks more vulnerable than when he is there.
So how much longer will he be around? The World Cup in 2015 is a target, and Kallis concedes he'll need to pace himself to get to that start line.
"No place is guaranteed in any side so I've got to carry on putting in the results.
"Certainly it's a goal of mine but we'll take it season by season. At this stage the body is still feeling good and the mind is still strong too."
He knows he'll have to sit out the odd series and will rely on his former team mate, now South African coach, Gary Kirsten, as a key sounding board.
"We've got a pretty open relationship so if I go to Gary and say I'm feeling a little tired, or feeling good, we can always discuss it. He knows my game. Managing oneself and rest is going to be the key point.
"And South African cricket is far more important than the individual."
Which doesn't sound much like someone who puts self first.
Comparison
Garry Sobers (West Indies) 93, 8032 at 57.78, 235 at 34.03
Imran Khan (Pakistan) 88, 3807 at 37.69, 362 at 22.81
Keith Miller (Australia) 55, 2958 at 36.97, 170 at 22.97
Shaun Pollock (South Africa) 108, 3781 at 32.31, 421 at 23.11
Ian Botham (England) 102, 5200 at 33.54, 383 at 28.4
Andrew Flintoff (England) 79, 3845 at 31.77, 226 at 32.78
Kapil Dev (India) 131, 5248 at 31.05, 434 at 29.64
Daniel Vettori (NZ) 107, 4381 at 30.85, 355 at 33.43
Richard Hadlee (NZ) 86, 3124 at 27.16, 431 at 22.29
Kallis
Tests: 149, 12177 runs at 56.9, 273 wickets at 32.4
ODIs: 319, 11,481 runs at 45.55, 267 wickets at 31.76
T20: 16, 512 runs at 34.13, 5 wickets at 45.8
