After the Test series in England in 2014, the Indian team hit a low, with a good start turning into a 3-1 defeat. Virat Kohli's form was among the main concerns. He had aggregated just 134 runs across five Tests, for one of his worst series returns ever, and the second-lowest he has averaged in a Test series across his career.

It was against this backdrop that the BCCI rang in changes to the coaching staff, with Ravi Shastri brought in as team director, and the trio of Sanjay Bangar, B Arun and R Sridhar brought in as batting, bowling and fielding coaches respectively. Since the start of the limited-overs series against England that followed, till the end of India's recent tour of West Indies, Bangar remained a constant in the team. His five-year tenure with the team was marked by more highs than lows, with Kohli, in particular, discovering a whole new gear in his batting from 2014-15 onwards. In an email interview with ESPNcricinfo, Bangar spoke about the challenges of his tenure, coaching Kohli, his thoughts on Rohit Sharma as a Test opener, and much more. Excerpts:

Rohit Sharma is set to open in Test cricket. What's your view on this?

At the moment, there is no place in the settled middle order in the Test team. Opening will be a new challenge for him, since he has rarely done it in the longer formats. But the advantage is that he will get to bat against a hard ball with plenty of gaps in the field. He will also not have to wait for his turn to bat, which will save his mental energy.

If he succeeds, his style of play will be extremely helpful to the team. It might result in being able to successfully chase down targets that we haven't achieved in the past, like in Cape Town and Edgbaston.

You have opened in Tests yourself. What does Rohit need do to succeed?

The key to his success will be if he maintains his individual style of play. He has to maintain his individuality.

When you look back at your coaching tenure, what is the thing that makes you proudest?

It has been a memorable journey [India going] from No. 7 in the world to No. 1 in Test cricket. The team won 30 out of 52 Test matches played, including 13 overseas Test victories. In ODI cricket, the team won in all overseas countries convincingly. Overall, the team won 82 out of 122 matches. So it gives me immense pride that I was part of this phase of Indian cricket, for which I am grateful to the BCCI and to all the head coaches I worked with - Duncan [Fletcher], Ravi [Shastri] and Anil [Kumble] - for giving me an opportunity to serve the Indian cricket team for five consecutive years.

What was your most challenging Test series as batting coach?

I believe that South African conditions are the most challenging in the international circuit, especially Cape Town and Johannesburg. We faced those conditions on our tour of 2018, and we also had very little time to adjust there - precisely six days before the first Test started. Those Test matches were the toughest one could encounter. The team is very proud of one of the most courageous displays by our batting group in Johannesburg in a memorable victory. And then to go on and dominate the ODI series and win it 5-1 was equally praiseworthy.

What are the changes you introduced in the Test batting line-up once you had settled down as coach?

We had extensive simulated preparations, tailored to the conditions we were likely to play in. That allowed us to overcome the challenges we faced, eight out of ten times. We developed a better understanding of angles, and how to maximise them in terms of run-scoring.

In the shorter format, we paid great attention to strike-rotation targets. I thought the work ethic of the batting group around these factors helped us deliver consistent results. We also assessed the goals and processes we had set up on a regular basis.

Ajinkya Rahane, India's Test vice-captain, went through an extended phase without a big score before he corrected that on the West Indies tour recently. What were the challenges of working with a senior batsman like Rahane?

Rahane missed out on converting a lot of fifties into hundreds in the last 18 months or so, but otherwise, he contributed in all our overseas victories. He contributed in Johannesburg, in Nottingham and in Adelaide.

We worked a lot on leading with his head and shoulder to get a proper stride into the shot, and also on finishing his trigger movements before the ball was released. I was very happy for him that he eventually crossed the three-figure mark in West Indies, where once again he played a pivotal role under seaming conditions.

He has been very gracious in acknowledging that the things we've worked on together have helped him at various points. [Rahane spoke about Bangar's inputs after scoring twin centuries in the Delhi Test against South Africa in 2015, having come into the match with only 39 runs in three Tests before that.]

Another batsman who has openly acknowledged your hand in his success is Virat Kohli. Can you talk about the relationship with him?

The thing that is unique with Virat is that he is always on the lookout for improving his game. He was willing to make minor adjustments suggested, if he believed it could help him. So we worked on aspects like width of his stance, his backlift, his head position etc.

You came on board right after Kohli had perhaps his lowest phase as a batsman in England in 2014. What did you focus on?
That time the positioning of his back-foot toe was towards cover-point at the time of release, which led to his hips opening. That also did not allow his bat's downswing to come in a vertical plane. He worked tirelessly to iron out those flaws.

How do you assess India's batting overseas?

Our batting in Australia, in 2014-15 and 2018-19 was outstanding, amongst the best ever by a visiting side. The top-order batting in particular was very good across all tours.

In overseas conditions, perhaps we lacked runs lower down the order. We have allrounders in the spin department, which helps in India, but in overseas conditions, we didn't have as many fast-bowling allrounders. Our top and middle order out-batted the opposition, but the lower order did better for the opposition.

During your tenure, India's batting numbers were the best in the world across various parameters. How do you look back at that?

The team management was able to achieve a mindset shift of playing outside their [players'] comfort zones by often batting first, irrespective of the conditions. I am very happy with the results achieved not only by the top order but also by Wriddhiman Saha, Ravindra Jadeja, R Ashwin and Bhuvneshwar Kumar in the lower order. Credit to the work the players put in and their drive to achieve excellence.

How do you assess India's T20I performance, which is relatively below what's at the Test and ODI levels in spite of the IPL?

All our preparations to this point in T20 cricket were done keeping an eye on the 50-overs World Cup. However, the current set up will have a sufficient number of T20I matches before two T20 World Cups are played in consecutive years. So, from a combination point of view, it gives enough opportunities for the players to be exposed to match situations relating to their roles.

Apart from team success, what are the most memorable moments you've had with the team during these five years?
I shall fondly remember the gratitude expressed by all the batsmen to me for the performances that we were able to create collectively.

What will you miss?

I'll miss singing the national anthem, and helping young people achieve their dreams.

Saurabh Somani is an assistant editor at ESPNcricinfo