Gambhir's problem is mindset, not technique
When Gautam Gambhir started out, there was much to like about his batting.
He had nimble footwork for an opener, which made him an exceptionally good player against spinners. When a spinner flighted the ball, he would use his feet effectively to reach the pitch of the delivery. His eagerness to do so forced bowlers to shorten their length, to which Gambhir responded beautifully by going deep into his crease to create room.
Against the quicker men, he didn't possess the tightest of techniques, but like all good players, he found a way around it. He would always be looking for runs, which meant a lot of dabbing and running to rotate the strike, and also punishing anything that landed in his striking zone. He rarely missed out on an opportunity to score.
In addition to the ability to punish loose balls, he also mastered the art of making every start count and of scoring big hundreds. His hunger for runs and penchant for batting for long made up for the minor technical deficiencies.
While these qualities were enough to bring success initially in international cricket, Gambhir's technical imperfections showed up when the going got tough. Unfortunately for him, these snags were related to each other, which meant that one faux pas would lead to the other.
When he stood in his stance, his head had the tendency to fall towards the off side, and that resulted in a very short-and-across front-foot stride. The moment the head falls, the judgement of line gets blurred. Balls pitching on the line of the fourth or fifth stump seem to be pitching on off-stump, and instead of leaving them alone, you tend to fish at them. The ones pitching on middle seem to be drifting down the leg side, and hence you attempt to play them towards square leg or midwicket instead of straight. It goes without saying that the moment you miss the ball, you are caught dead in front.
Gary Kirsten was quick to not only point out these lapses but also correct them. He asked Gambhir to position his head on top of his right shoulder while in the stance, which took care of his habit of leaning on the bat. Once the head stopped falling, Gambhir started leaving alone the balls that were meant to be left alone.
The second adjustment was to take the forward stride towards the bowler, which resulted in the front foot going a lot straighter. In addition, he started playing the ball a lot straighter and also very late.
This tweaking worked well for Gambhir, kickstarting one of his most successful periods in international cricket. The best part about his progress was that while he was wiping out minor flaws in his technique, he also kept building on his strengths. The results were there for everyone to see, which included him reaching the top of the Test batting rankings.
In the last couple of years, though, a rather significant pattern has emerged in Gambhir's international performances. He has continued to be among the runs in the shorter formats, but has struggled to put together big innings in the longer format on a regular basis. He seems to come out with an attacking mindset in limited-overs cricket, which results in decisive foot movements, but oddly, he seems to be in two minds in the longer format. His "neither here nor there" frame of mind is among the major reasons for the decline in his Test form.
Perhaps it has something to do with the (bad) habits one tends to pick up while playing too much short-format cricket. Though Gambhir has shots all around the wicket, he prefers dabbing the ball down to the third-man region. While it's an easy single in the shorter formats, fielders at slips and gully plug that hole neatly in Test cricket. It cannot be the case that Gambhir is not aware of the repercussions of opening the face of his bat to run the ball down fine, but at times instincts overrule rational thinking.
In Australia and against New Zealand, he tried hard to be more judicious about the balls he played and left around the off stump. But just one error of judgement was enough to end his resolve each time; after leaving a few balls alone, he would be lured into playing one that too should have been left alone.
Gambhir's lack of Test runs isn't because of a technical failing, so he will find it hard to look for answers in manuals or from cricket coaches. His problem is with his mindset, particularly about controlling his instincts. It may not be a bad idea for him to spend a few hours with Sachin Tendulkar and pick his brains on the innings Tendulkar played in Sydney in 2004. In that particular innings of 241 not out, Tendulkar showed immense control over his faculties by not playing a single cover drive in the entire innings. Gambhir will have to follow suit by telling himself that there isn't a single run available behind the stumps to him in Test cricket. Also, perhaps he needs to make a resolution to play only in front of the stumps to fast bowlers.
He may only be a couple of good innings away from finding prime form, but he's also only a couple of poor innings away from getting dropped from the team. Now it's mind over matter.