Former Indian batting coach Vikram Rathour believes skipper Shubman Gill's incredible batting transformation began at a critical point during the second Test of last year's home series against England at Vizag. The match in question saw the right-hander score a brilliant second innings century to help India win by 106 runs and level the series.However, moments before Tea on Day 3, Gill played an incomprehensible reverse-sweep off Shoaib Bashir to lose his wicket. It led to an Indian collapse from 211/4 to 255 all out, which fortunately did not cost the side.Recalling his conversation with Gill after the dismissal, Rathour recently told Cricbuzz:"I asked, 'okay, tell me who are the five best batters in this century of Test cricket?' He named the usuals: Sachin Tendulkar, Joe Root, Kane Williamson, Steve Smith and Virat Kohli... and I said, tell me one who would've played that shot in that moment. He was quiet. 'Maybe nobody.'So I asked him, why did you go for that shot? And he said, 'you told us to sweep and reverse-sweep on turning tracks and there were no fielders there, so the shot was on."He added:"It's not that those five couldn't play it. It just wasn't needed. Test cricket is about playing the moment. You don't play a shot because you have it. You play what the team needs. And I think that is the biggest change I can see in him now."Gill remained inconsistent in Tests until the start of the ongoing England series and was dropped from the XI in the penultimate Test of India's previous series in Australia."Previously there was a slight gap" - Vikram Rathour on changes in Shubman Gill's battingVikram Rathour pointed to the subtle technical changes in Shubman Gill's batting, including the bat staying close to the body, as the key reason behind his incredible run in the ongoing England series. The 25-year-old has been on a historic record-breaking spree, scoring 722 runs at an average of 90.25 with four centuries thus far after four Tests.Gill already has the record for the highest score by an Indian batter in England and an Indian captain with his 269 in the second Test at Edgbaston."In his stance, I can see his elbow of the backhand from the straight [view]. He's trying to keep his front shoulder a little closed because he is trying to keep the bat closer to the body. Previously there was a slight gap when he was defending on the front foot with the bat coming a little across and the ball would go through," said Rathour (via the aforementioned source).He concluded:"Earlier, his trigger used to be a big stride back, he used to do it very early also. In England, actually, the lesser you move, the better you are, the more stable you are and the timing of the trigger is very important."Gill trails only Sunil Gavaskar (774 and 732 runs) for the most runs by an Indian batter in a Test series, with a game to be played at the Oval, starting July 31.