After the fourth ODI in Chennai, MS Dhoni stated the new ODI rules, including the presence of a fifth fielder outside the 30-yard circle in the last 10 overs, had made slogging difficult. On the eve of the series-deciding fifth ODI in Mumbai, Virat Kohli said that the change had made the period between the 20th and 40th overs - previously seen to be the quieter part of the game - as important as the last 10 overs had been under the previous rules.

"Under the previous rules, it was always that you take the game until the end and keep wickets in hand so that you can have a major boost at the end to chase scores down," Kohli explained. "But the need of the hour in this format or new rules is that you stay ahead of the game all the time, which I think is a challenge in itself. That's why physically, it exerts you even more because you don't have any time to relax or get your foot off the pedal because the game just keeps going away from you.

"So I think it's very difficult to leave a 15 or 20 run-ball gap in the end. In the last 10, you can't afford to leave 80 in this new rule scenario. So I think you need to stay ahead of the game, so you are chasing 5.5, max six in the last overs so you can still rotate the strike. Play run-a-ball and still get your score chased. So I think in this new rule scenario, overs 20-40 have become the new 40-50 as they say. So smart cricket is required for a longer period in this particular situation and that is one of the challenges that I have experienced. It hasn't been easy to adapt immediately but, as I said, you need to stay ahead of what's happening, so you have to figure out what needs to be done in different situations."

The five-match series is the first played in India under the new ODI match rules, which were introduced in June this year. Kohli said the conditions also contributed to the impact that the rules had, particularly as the pitch wore on and the ball got older.

"To put things in a nutshell, it has become a little more difficult compared to the rules in the past, specially the subcontinent, surprisingly, because the ball is getting rough and old and the wicket doesn't have too much pace and it's difficult to get the ball away to the boundary," he said. "I don't think it will be as difficult outside the subcontinent because it may not be such a bad idea to have five fielders. You will have more chances to rotate the strike and play cricket with lesser risk, not having to clear the boundary every second ball. You can get a boundary an over and still have seven-eight runs an over.

"Plus with the new rules, exactly what happened in the last game needs to be done - more of running, more of mental preparation to go out there and run more than hit boundaries. It's probably one thing I was looking to do in the last game as well, and trying to keep the dot balls to a minimum as well is a key in such a format. It does get a bit difficult, especially in the later half of the innings, so the whole idea is rotate the strike more and rely less on boundaries. That, I think requires a bit more mental discipline."

The challenge in the final overs places emphasis on the need for a team to fall into a brisk scoring pattern early without losing too many wickets and maintain it across the innings, unlike in the past where the middle overs were often a plateau between the spurts in run-scoring at the start and at the death. It also brings into focus the role of a No. 3 batsman who is tasked with controlling the innings - either regaining tempo after the loss of early wickets, or ensuring that the team maintains a steady pace.

"The reason I feel at home at No. 3 is because I have played a lot of games there. I think that's where I have realised what my game is at the international level"

A sign of that was evident in Kohli's century in Chennai, where he was the common strand in two century partnerships that ensured the failure of the openers did not hurt the side too much. The way he rotated the strike - 84 of his 138 runs came off singles and twos in sapping heat - was a sign of his evolution as a batsman, according to MS Dhoni. It was also an extension of the form he showed in Rajkot where he returned to the No. 3 position after coming in at No. 4 in the first two ODIs. It is a position, Kohli said, he felt at home with, one where he was confident of controlling the game.

"The reason I feel at home at No. 3 is because I have played a lot of games there," he explained. "I think that's where I have realised what my game is at the international level - I played at No. 4 pretty later on. So I am pretty sure and confident of my own ability at No. 3, that I can stabilise the innings and hold one end so that the team can benefit from it. That's always my mindset, even when we look to chase a score. If I get in at No. 3, I have the opportunity to analyse what's going on in the game, look at the scoreboard and play my game accordingly and choose what bowlers to hit boundaries off at different times in the game. I've been able to execute that so I feel more confident that I can control the game better.

"As a batting unit, you need one guy to bat through . Of late, Rohit [Sharma] has been doing that job for us pretty well. That was the idea that I felt very good about in the last game that even if one of the two guys - Rohit and Shikhar [Dhawan]- don't work, at least I can have that mindset of batting through for the team."

Kohli brushed off the questions over Dhawan's form, saying the opener - who has had a lean run in the series so far - was a big-match player and could well find his touch in the decider at the Wankhede Stadium. He also said that the team's batsmen were in a "good mental space" after their win in Chennai, having pitched in with a collective performance.

"We hadn't collectively played good cricket before the last game and we all knew that so it was up to us to get all the three formats together and get a collective performance in and that's exactly what happened in the last game," he said. "And as MS [Dhoni] has mentioned in the past as well, that everyone has been batting well but because of these rule changes, sometimes you go out there in the middle and suddenly you are not able to hit boundaries. So you feel like you don't quite know what to do in that situation. I think at that time game awareness is very important which all the batsmen collectively together were not able to do, previously. So we figured out what needs to be done and we were able to execute that."

Rachna Shetty is a senior sub-editor at ESPNcricinfo