The soul of fast bowling is pace. Yet the backbone of fast bowling has always been control. Accuracy. Consistency. These three are intangibles, which a fast bowler learns as he runs in at different venues, in both hostile and hospitable conditions. During the course of this improvisation the fast bowler becomes a good seamer, moving up to very good in some cases, and dominant in others. And when a team is blessed with more than one dominant fast bowler, the pace battery - as was portrayed richly by Clive Lloyd's quartet during the dominance of West Indies in the 1970s and '80s - becomes fearsome.
Never before could you describe Indian fast bowling as fearsome. Kapil Dev was an outstanding talent who ploughed a lonely furrow. Zaheer Khan, too, was exceptional, especially with the old ball during the latter part of his career. But not fearsome. As far as quartets went, India never went beyond the spinners - Bishan Bedi, Bhagwath Chandrasekhar, Erapalli Prasanna and S Venkataraghavan.
But India are the No. 1 Test team in the world at present and, increasingly so, the fast bowlers are playing a dominant role as Virat Kohli's team aims to win more overseas. The current Indian pace attack, comprising Ishant Sharma, Mohammed Shami, Jasprit Bumrah, Umesh Yadav, and Bhuvneshwar Kumar, who has just recovered from injury, is steadily becoming a fearsome unit. They are not yet as fearsome as the Australian and South African contingents but as the ongoing England series has shown, this Indian unit can sting.
India's fast bowlers have clocked better and better speeds throughout this series against England. They have managed to swing the ball more than at any other time in their careers. Importantly, during the course of the series, all the main fast bowlers have fine-tuned their strengths, as Ishant and Bumrah did in the first session on Thursday to throttle England's top order.
You need to just check some of the responses of England's batsmen to understand the pressure they were put under. Keaton Jennings played an explosive inswinger from Bumrah as if he was trying to avoid stepping over a landmine; Joe Root lost his balance and nearly fell over attempting to counter late swing from Ishant; Alastair Cook said "ooh" more than once as he was constantly being squared up by Ishant; Jonny Bairstow appeared to be batting blindfolded as Ishant beat his defence effortlessly with deliveries that curved through the wide gap between bat and pad and had Rishabh Pant throw himself about. Stokes widened his eyes in disbelief at the pronounced and acute movement Shami was getting to beat his outside edge, pitching full, at 89mph.
Although Ishant, who took his 250th wicket today, remains the head boy of the bowling group, it was Bumrah, whose incisive breakthroughs early had hurt England at Trent Bridge, who hurt them again in the first session today. Since his Test debut in South Africa, Bumrah has continued to be the X-factor. Yes, his bowling action has played a significant role, but an equally crucial element of his success is his fast-bowling nous.
Ten minutes into the morning and he had sent back his first victim with a mental gash that Jennings might need to visit a psychologist to sort out. It was a proper set-up. The first three deliveries of his second over, Bumrah pitched all three on good length, moved all three away, which Jennings left alone. The fourth delivery, Bumrah pushed the length fuller. The line remained the same. The ball, upon pitching, swerved in sharply. Jennings had no idea it was an incoming delivery. He had already decided to leave it. He was stunned by the movement. It was a stunning delivery. As a post-mortem of the wicket later showed, Bumrah had directed the seam towards leg slip.
Watching from the balcony, knees up, one man might have applauded the set-up - James Anderson. Never a bad thing to learn from the masters. The thing that Indians have learnt from Anderson is discipline. With every match they have probed the batsmen. They have become more assured. Gone are the days when MS Dhoni would direct traffic. Kohli might micro-manage the field, but the fast bowlers take care of the bowling plans. The numbers are proving them right. The strike rate of the Indian pacers this series - 44.2 - is the best by any overseas team in England since the one-off Centenary Test of 1980.
How has this Indian pace attack shown such sharp progress? The biggest factor is their fitness. That is the biggest change in culture from the past. Being fit has allowed the bowlers to hit optimum speeds and allowed them to bowl long spells, as Bumrah showed this morning with eight good overs in his first stint. Being fit has helped bowlers to come back with fresh energy in each spell.
Every bowler has shown the patience and understanding to bowl to a situation. The bad habits that accompanied them in the past, especially of erring in line and length, have been reduced. Take Ishant. In this series, while bowling during the first 15 overs of an innings, he has bowled more full deliveries than back of a length, a weakness that till recently seemed incurable.
India now possess a group of fast bowlers that can hurt the opposition in different ways. But by no means are they complete. As the expectations grow with every series, the challenges will grow. Can they maintain their good form in Australia later this year? A weak England batting line-up, both vulnerable and fragile, has added to the character and weight of the Indian fast bowling unit. Can they maintain the stranglehold in the face of big partnerships? Can they attack and defend and show controlled aggression, a hallmark of good fast-bowling attacks?
On evidence so far this series, they have the skills and the temperament. Despite Sam Curran's impressive rearguard - for the second time this series - India might end day one thinking they have the edge in the match. And that is courtesy India's pace line-up, which has been both crude and shrewd.