For a nation starved of fast bowlers, the advent of Kapil Dev was a godsend. His batting was pretty handy as well, but there's little doubt that his major contribution was as a pace bowler, offering India an attacking option with the new ball that they had sorely lacked till then.
If the task of bowling fast on flat pitches wore Kapil down, he did remarkably well to camouflage that wear and tear over an international career that stretched 16 years.
He announced himself in no uncertain terms in his first series, exhibiting pace and aggression hitherto unseen among Indian bowlers, but in statistical terms the returns from that series were meagre - seven wickets at an average of more than 60. In his first 10 Tests, he conceded more than 39 runs per wicket, and his batting was a stronger suit than his bowling. Sixteen wickets in four Tests against England started the golden run with the ball, and he followed that with 28 wickets in the home series against Australia and 32 in six Tests against Pakistan at an average of less than 18.
Those performances signalled a peak in Kapil's bowling career, when the pace was sharp, the outswinger working to perfection, and the wickets coming his way at a quick rate. In the 13 series he played between July 1979 and December 1983, Kapil's bowling average went beyond 32 in only three series, while seven times he averaged less than 26. That was also the period when he averaged more than four wickets per Test, and took a five-for 17 times in 52 Tests.
He still turned in lion-hearted performances with the ball after that, but not with the same consistency: in 69 Tests from the beginning of 1984, Kapil's wicket tally dropped to 2.7 per Test, and he also went an entire series - three Tests against Australia at home in 1986 - without a wicket. His batting, though, went up a notch, thus ensuring that his batting average was higher than his bowling average in each of those three periods of his Test career. Of his eight Test centuries, five came during this phase.