This week will be a very important one for world cricket. Two young batsmen, competing to be the best in the world, will lead their teams into two very difficult Test series. Steve Smith will lead Australia in his first full series (against New Zealand) after Michael Clarke’s retirement while Virat Kohli gets set to captain India in Test cricket for the first time at home – vs South Africa.Also read: 1st Test – Onus on Virat Kohli as India look to tame South Africa Smith and Kohli had locked horns against each other – in that acrimonious series Test series in Australia earlier in the year. MS Dhoni had missed out in Adelaide, then retired before the Sydney Test, while Clarke was injured after the opening match, leaving the young turks in charge of their sides – consequently, there were bitter wars of words, ugly sledging, fines and threats of more severe action from the International Cricket Council and most importantly – some riveting cricket. And most of that riveting cricket was played by Messrs Kohli and Smith, who made it a contest of centuries.Both Smith and Kohli have taken over from great statesmen. Yes, Clarke was a motor-mouth early in his career and showed glimpses of aggression as the sunset neared (remember his lines to James Anderson as Mitchell Johnson marked his run-up at the Ashes in 2013? “Get ready for a broken ?? arm), but mostly he earned the respect of fans and media the world over. Dhoni was even calmer, never indulging in verbal assaults, never indulging in exaggerated celebrations and always ensuring his men remained in check.advertisementAlso read: Aus vs NZ – Smith hits back at McCullum for labelling him immature But times are about to change. Smith, who is also Australia’s ODI captain, has been clear in his approach – victory at all costs. When he refused to take back the appeal against Ben Stokes during the Lord’s ODI this year, the benchmark was set. New Zealand skipper Brendon McCullum had called Smith “immature” – Smith said “right back at ya”. These two men will face off against each other in the opening Test in Brisbane this week. Some polite exchange that before the start of a five-day match.Kohli, who likes to rub the opposition the wrong way as well, has faced some criticism too. His constant stress on playing aggressive and ruthless cricket may have led a few of his teammates to get carried away. Ishant Sharma, who bowled himself back to form in Sri Lanka, was saddled with a one-match ban after his over-the-top celebrations and sledging of the Lankan batsmen. Some said Kohli should have tamed Ishant while others believe the young captain should be allowed to express himself naturally.While Smith vs Kohli as captains will always be explosive, it will be interesting to see how they deal against cooler skippers. Smith and Kohli love a good fight (read as verbal onslaughts on the cricket field), while McCullum and Hashim Amla are far more poised. But whatever any of these captains do, it will decide how world cricket shapes up – India and Australia besides boasting of the two richest cricket boards in the world, have the largest fan bases and some of the most talented players. The onfield rivalry between these two countries has become legendary – a few Aussie players have even touted their contests vs India a bigger high than the Ashes!Sourav Ganguly and Steve Waugh’s rivalry as skippers and the then India captain’s tactics to irritate Waugh are now part of cricketing folklore. After a period of statesmanship, Kohli and Smith will mark the beginning of a hostile era – make no mistake about it. There will be fireworks on the field – both men will coax the best and the worst out of their players!