Gautam Gambhir knows the value of hundreds. Probably more than your average batsman. He had to fight through an ordinary start to his career, was dropped and forgotten, had to go back to domestic cricket when at times he felt like quitting the game altogether, and when he came back in 2008, all the hard work he put in would yield only half-centuries.

The comeback began in the series of Murali and Mendis in Sri Lanka. Gambhir was India's second-best batsman on the tour but had only three half-centuries to show. Then another fifty followed, against Australia. Gambhir was anxious; he worried he wouldn't be taken seriously as a batsman if he didn't score centuries when in good form, and without hundreds what buffer would he have when form paled? As he walked back after one of those half-fulfilling innings, he heard people say he was good only for fifties.

Of course, once he crossed the line once, Gambhir crossed it many times: eight times in 10 Tests. Two of those came in New Zealand - among them a second-innings marathon for 643 minutes to save a Test. The world respected him now; bowlers feared him, especially with Virender Sehwag at the other end; but bigger tests remained: those of seaming conditions and top-quality bowling in South Africa and England.

At this point, Gambhir slipped back into no-hundreds mode. Scores of 5, 80, 93 and 64 in South Africa teased you. The 80 in Centurion promised a fight for the draw, the best India could have salvaged after a disastrous first dig, but they fell short. Had the 93 in the first innings at Newlands extended longer, in partnership with Sachin Tendulkar in imperious form, he could have set up a big lead. The final innings of the series was up his alley: injured and already ruled out of the ODIs, and with massive amounts of rough outside his off stump, he batted 271 minutes for just 64 to save the match, but again, no century.

It sounds good to hear that hundreds don't matter, but would MS Dhoni really have been the Man of the Match in the World Cup final had Gambhir added three to his 97, an innings that rescued India after the early loss of Sehwag and Tendulkar? Would we be doubting Gambhir now if he had converted two of those innings in South Africa into hundreds? Yes, Gambhir was doing the job the team needed, but he wasn't leaving himself too much to live off in bad times.

The bad times well and truly arrived in England. The opposition's bowling unit fired all together, and ruthlessly. Injuries showed up too. Feeling his way back into Test cricket, Gambhir scored only two half-centuries at home against West Indies. Slowly, unnoticed because Gambhir was putting in the regular important hand, it began to look ugly.

Now these things cannot be controlled, but Gambhir is hardly a stranger to injury. Of India's last four overseas Test tours, he has missed one altogether, and he has been injured for four Tests on the other three. He has played just six of India's last 13 away Tests. Fairly or unfairly, tongues begin to wag. Not long ago he was the man Gary Kirsten would have nominated if his life depended on one innings. Now skills, commitment and bravery are all being questioned.

Those numbers and injuries are the anatomy of a poor year - one without an international century. He last scored an international hundred on December 4 last year, against New Zealand in a home ODI. If he doesn't score one in the first three Tests in Australia, he will have spent two years without a Test hundred.

You could sense he was nervous during the West Indies series at home. You could see he needed runs behind him to feel comfortable again. A small indication of it was when West Indies didn't provide him leg-side deliveries early in Mumbai, and he chased wide deliveries until he got off the mark. Once he hit a boundary to score his first runs, he settled down.

Gambhir is an intense individual. He admits to being too hard on himself. In 2009, in the middle of a purple patch, he told ESPNcricinfo he still felt insecure after one low score. Having come out of the pits once, Gambhir says he is not too worried now. A day before boarding the flight to Australia he told ESPNcricinfo: "People will always recognise a batsman if he scores a hundred. And when everyone keeps talking about [how] you have not scored a hundred, it plays on your mind. It is very difficult to take it out of your system. But as I said, if I keep thinking too much, I might not be able to score what I have been scoring and giving good starts. Then I would only be thinking about not scoring a hundred. You start from nought, and from nought to a hundred is a long, long journey."

Of all the five men who are certainties in the Indian batting line-up, it is to Gambhir that this tour to Australia is most important. Yes, this is the last one for the big three, and that will bring its sense of importance, but Gambhir is the one who has stuff to prove. His is still a young career. He has not scored centuries in South Africa and England, he is yet to play in Australia. In his 12 Tests outside India, not counting Bangladesh and Zimbabwe, he has conquered New Zealand, has managed to live in South Africa and Sri Lanka, and been conquered by England.

It is a middling return, despite his having really failed only in England. His average of 53.30 when he has opened in such Tests is impressive, behind only Manoj Prabhakar among Indian openers. Of the three big tests for an Indian opener - tours to England, South Africa and Australia - this coming one will be the least tough. Yes, there will be more bounce, but also less seam movement. And England and South Africa have better attacks at the moment.

Gambhir's first task will be to play the whole series, through fitness and through good starts, which he and Sehwag did in the home series against West Indies. That's all he says he wants to think of right now, not centuries. If he does get those starts he will need to make the most of them because India don't travel to a testing venue for two full years after this.