In T20 cricket the two most difficult phases to bowl in are the first six overs and the last four. In the early years of the IPL, the majority of the overs in these periods were bowled by the overseas bowlers, but gradually the Indian internationals began to share this responsibility. Still, while Jasprit Bumrah and Bhuvneshwar Kumar grew into two of the finest fast bowlers in the world in these phases of a T20, the rest of the young - and even older - Indian fast bowlers were still not up to the mark.
A curtailed IPL does not provide us with a reasonable sample size of matches to form a firm opinion, but there was enough to suggest that there has been a significant shift in the roles and responsibilities of young uncapped Indian fast bowlers in the tournament.
In Chennai, Harshal Patel of the Royal Challengers Bangalore was assigned the duty of bowling his four overs in the second half of the innings. Chetan Sakariya of the Rajasthan Royals bowled both with the new ball and in the death overs. And Avesh Khan of the Delhi Capitals was extremely impressive in all phases of the game. These three Indian medium-pacers were the story of the 29 games played in this year's IPL so far.
Sakariya started as an unknown but immediately made an impression. He has the skills to make the ball move both ways in the air, has both back-of-the-hand and offcutter slower ones, and the temperament needed to bowl wide yorkers. He isn't rapid in the air but has shown that he has the bowling smarts to pick the right options.
The Royals had a preset plan to have deep point and deep square leg fielders from the first ball. That kind of field forces your hand as a bowler, often making you bowl shorter. While bowling to that kind of field is not ideal for someone who isn't really fast and prefers to rely on swing instead, Sakariya adapted and rarely bowled a boundary ball with the new ball. Every time he was taken for runs, the batters had to take risks. In the death overs, he not only backed his plans, he also was not perturbed by the reputation of the batter he was bowling to.
There are two things in particular that you look for in a young bowler. One, how he reacts to a six or four - that is, what will his follow-up ball be? And two, how does he shape up in a contest against the best in the world? The likes of Kieron Pollard, Andre Russell and AB de Villiers are capable of smashing good balls for sixes and that puts a lot of experienced bowlers off their plans, making them end up bowling half-volleys as we scratch our heads and wonder why they didn't just bowl a wide yorker. Sakariya stood tall in these contests, though, as I said, the sample size is small.
Khan was assigned a much tougher role than Sakariya. He wasn't bowling the first and third overs but rather the fifth or sixth - the toughest of the powerplay overs. Since Anrich Nortje was missing and Kagiso Rabada seemed a little off-colour, Khan was often even brought on to bowl the 18th and 20th overs.
He is tall, gets good bounce and is fairly quick in the air. This season we saw him pitch the ball fuller when it was new, and land yorkers close to perfectly in the death overs. He doesn't have a great slower one but he seemed to be in a good place to make the best of what he does have. That's another thing that makes a big difference: if you don't have a good slower one, the ones you do attempt are probably going to disappear. It is the same with misdirected yorkers. The understanding of one's abilities and skills is vital if you are to trust them while choosing from the many options every ball presents.
Patel, the holder of the purple cap, seemed to turn over a new leaf in his IPL career this year. There aren't many categories of fast bowlers in T20 cricket - the two main ones are those who are good with the new ball and the ones who specialise in bowling at the death. Patel might belong to the latter group, but impressively, he made the most of his skills on the slow surface in Chennai. Once the ball got old, it started to grip the pitch, and the bigger boundaries allowed the fast bowlers to roll their fingers over the ball with more confidence. T20 cricket isn't long enough for bowlers to set up dismissals but it does allow you to use the match situation. Patel often started his spells around the 12th over - when the opposition is typically looking to break free. He used his offcutter variation to take the pace off the ball, and otherwise bowled really straight - though not attempting to get under the bat.
In theory it sounds really simple because that's more or less what you need to do on a slowing surface, but it requires discipline and confidence to stick to the plan. We've often seen bowlers try something radically different on the fifth ball of an over after having contained the batters for the first four balls. The anticipation that they are going to be hit makes them do things differently even when normal service is working just fine.
Patel, as expected, struggled a little when RCB's campaign moved to the Wankhede and Ahmedabad but two expensive 20th overs must not take away from the amazing things he did before that.

Former India opener Aakash Chopra is the author of three books, the latest of which is The Insider: Decoding the craft of cricket. @cricketaakash