Among all Indian fast bowlers who've taken at least 10 wickets in home Tests, Mohammed Shami and Umesh Yadav have the best strike rates. It's a fact Virat Kohli is well aware of - he brought it up himself in his post-match press conference after India wrapped up a 3-0 Test series victory over South Africa in Ranchi.

What makes Shami and Umesh so dangerous in Indian conditions? According to Kohli, it stems from the attacking lines they bowl, and their fitness, which allows them to bowl relentlessly in those areas.

"If you look at these two guys, their strike rate is probably the best in Indian conditions in history, which tells you that these guys hit the stumps and the pads more than anyone else before them." Kohli said. "It's again a great sign of the kind of intent that the bowlers are running in with now. The fitness levels obviously have gone up, so your brain is obviously supporting what you want to do, because your body also will support that workload.

"You bowl three good overs and if you're tired, then the other two [overs in the spell] are not as effective, and you lose the opportunity to take a wicket after creating pressure. But these guys are relentless, they're running in to just take wickets, bowl in areas that make batsmen uncomfortable.

"The focus was on spin [in the lead-up to the series], but the pacers have done the damage. We've become a multi-dimensional team now, and it's not [just] one thing that you need to counter when you're playing against us."

India's fast bowlers ended the series with a collective bowling average of 17.50. South Africa's quicks, in comparison, averaged 70.20.

After the first Test in Visakhapatnam, where Shami had run through South Africa in the fourth innings, Kohli had said Shami was capable of getting more help out of Indian pitches than anyone else he had seen. Asked how he and Umesh were able to get that sort of help while their South African counterparts could not, Kohli said it was mindset that set India's fast bowlers apart.

"We speak of doing things differently," Kohli said. "On a green pitch, say the openers walk into bat and feel like, 'well, the opposition hasn't gotten many runs, so we might not either', then you're not going to get runs. If you believe we can score runs on green wickets, you will get a hundred when the others don't. So it's about mindset.

"As fast bowlers, if you feel like there's nothing in the pitch but we can make something happen, you will make it happen, because that's the kind of effort you want to bowl with. If you look at a pitch and you just give up, then you're getting nothing out of it, so it's the mindset. They want to make things happen, they don't want easy cricket, they don't want easy situations, they want to have things which are challenging, and then they try to come on top, because it's going to do the team a lot of good if you do well in difficult scenarios.

"It's all about the mindset. They run in to bowl, they ask - even if the ball is doing a little bit - after the spinners have bowled, they immediately want the ball back, so they want to make an impact, they want to make breakthroughs, and I think it's about the positive mindset they've created for themselves."

When India went to South Africa last year and played on green, seaming pitches, they lost the first two Tests despite putting the hosts under pressure at various points, but came back to win the third in Johannesburg. The return tour didn't have anything like the same degree of competitiveness.

"Yeah, look, when we went to South Africa, we know that we competed in every game, and eventually ended up winning the last Test as well," Kohli said. "It was all about one session or maybe an hour of bad cricket that cost us games, so we understand that, to compete in conditions which are not yours, you need to be positive every single minute of every day on the field. If you let five minutes of negativity creep in, it's a downward slide from there.

"We understand that it can get difficult, but we have also applied a lot of pressure on the opposition, especially in our conditions, so it's difficult to keep up when the [other] team is playing so well, but yeah, focusing on the positives of our team, I don't think we allowed the opposition to get into any game, at any stage at all."

India handed a debut to Shahbaz Nadeem in the third Test, after he came into the squad as a late replacement for Kuldeep Yadav. Close to 15 years after his first-class debut, the left-arm spinner enjoyed an excellent Test debut, picking up four wickets and finishing the match with two in two balls. Kohli said India had always been aware of Nadeem's quality as a bowler.

"I've played with Nadeem before as well, Under-19 as well, and we've always known he's quite a skilful bowler, the kind of skill he has with his conventional left-arm spin," Kohli said. "He puts revolutions on the ball, his seam position is really good, bowls at a good pace, and when you've taken 420 wickets in first-class cricket, you can come and bowl four maidens straight up in a Test match [like Nadeem did]. He's capable of bowling in one area.

"I think he's made a very good start. He bowled with a lot of composure. It's amazing how things can change dramatically in life. Two days before the Test, he was in Kolkata, and from there he came here and played. He was not out with the bat, he pulled off an excellent run-out, and in both innings he bowled well, so I'm quite happy for him. I've known him for a long time. He's obviously a quality bowler, and for us to bring him in on this kind of track as a replacement, we already knew he has the quality. From here, he'll only keep building."