"The monkey is off his back!" exclaimed Robin Jackman as the ball ran away to the fine leg boundary. It's an analogy which will no doubt be repeated in newspapers across South Africa tomorrow morning as the nation's cricket writers go about the tricky task of finding new ways to describe just how good a cricketer Jacques Kallis is.

The statistics will be trotted out, jokes will be cracked about his new crop of hair and Kallis will deserve every platitude which comes his way. He is undoubtedly one of the finest all-rounders to have graced the game.

Maybe it's just me, but there seemed to be an anticlimax about him reaching his maiden Test double hundred. Judging from his reaction, it clearly meant something to him and his teammates, but how much beyond the fact that his detractors had lost a stick to beat him with is difficult to say.

He'll no longer be called the best batsman in the history of the game not to score a double, a dubious honour which passes on to Mark Waugh or Richie Richardson, depending on your tastes.

But would Kallis put this innings among the top five he's ever played? Or even the top ten? It might acquire additional value because he finally achieved The Double just when we'd all made peace with the fact that he never would, but he would be the first to admit that it was scored on a flat pitch under sunny skies against an Indian bowling line-up without its attack leader.

Surely he would put the 101 he made against a rampant Aussie attack containing Shane Warne, Glenn McGrath and an in-form Paul Reiffel to save South Africa from defeat on a turning MCG track in 1997 right at the top?

His 63 and 57 in Perth two years ago in an historic victory were probably worth more than the runs he made at Centurion these past few days. As he said at the close of today's play, scoring runs in tough victories are what mean the most to him.

It's unlikely he'd admit as much but one of the things which might be most disappointing at the end of his career is how many times his big scores have dug South Africa out of trouble, but not been enough to save them or produce victories. His 111 and 50 not out in Sydney in 2006 stands out, but such instances are littered throughout his list of Test high scores.

From that point of view, what makes this innings important is Kallis' relationship with his teammates. The impact he has had on them and how that has come full circle to help him achieve the one feat his record was lacking.

The two men who bat around Kallis in the order - Hashim Amla and AB de Villiers - have made giant strides in the past two or three years. Both are among the best batsmen in the world at present - Amla has had his best year yet in both Test and one-day cricket while de Villiers has followed up South Africa's highest Test score with their fastest Test century.

Amla in particular speaks of the influence Kallis has had on him, but in turn the new-found solidity which Amla and de Villiers have provided has allowed Kallis to become a more attacking player.

He's often been described as a boring batsman who plays for his average, but in truth he was often batting to secure South Africa's survival. Since Amla and de Villiers came of age to provide that security, Kallis has come out of his shell and has a strike rate of 53 over the past two years.

That might not be Sehwag-esque, but compared to his career strike rate of 45 it shows how much more expansive he's become. His 201 not out was scored at a strike rate of 74, which might be the difference between the Proteas claiming 10 Indian wickets to go one-up and walking away from a dominant display with the series all square.

All told then, perhaps the best thing that can be said about The Double is that it puts into statistical terms - in a round-about kind of way - an intangible achievement which is actually one of Kallis' finest accomplishments. Namely the positive impact he has had in the maturation of South Africa's best middle order.