Vaibhav Sooryavanshi has scored 404 runs with a strike-rate of 237.64 at this year's IPL. Few have had a better view of the development of cricket's 15-year-old sensation Vaibhav Sooryavanshi than former England all-rounder Mike Yardy.

Yardy was in the opposing dugout when Sooryavanshi, then aged 12, played for India against England in an under-19 series. He was coach once more when the precocious left-hander toured England last summer - Sooryavanshi scored 143 in the fourth 50-over match in Worcester - and again when the teenager hammered an incredible 175 from 80 balls against England in the Under-19 World Cup final in February.

So, has he spotted a weakness? "Not really, no," Yardy tells BBC Sport. Yardy's tongue is slightly in his cheek - but that is a question now facing the world game. A batter not old enough to leave school in many corners of the globe, who used to travel three hours to the nearest major city for coaching at the age of eight, is currently taking down the very best bowlers around.

"The talent he has got, I don't know what to predict because I have never seen anything quite like it," Yardy says. Any suggestion the 12 months of white-ball success leading to the Under-19 World Cup final knock were some sort of fluke for Sooryavanshi has been banished at this year's Indian Premier League. Rajasthan Royals' opener followed his 35-ball century as a 14-year-old in last year's tournament - one which made him the youngest centurion in men's T20s - with a 36-ball century against Pat Cummins' Sunrisers Hyderabad two weeks ago.

The speed of those two tons has only been beaten by West Indies' T20 legend Chris Gayle in the IPL. Like Gayle, Sooryavanshi's innings are built on brutal boundary hitting, though he gets there in a different way. With a high yet unusual and whippy bat swing, his hands move away from his body as the bowler releases. He generates his power as the bat swishes back through the line to make contact. It led former England captain Michael Vaughan to muse this week whether Sooryavanshi could become the "greatest striker of a cricket ball of all time".

"His bat swing is quite unique," says former India international Deep Dasgupta, another who has had a front-row seat for the teenager's rise, through his commentary at the IPL. "It is not a taught bat swing. Batters go straight up and straight down - a linear path. This is more circular and wristy." Sooryavanshi begins in a conventional left-hander's stance After the ball is released, Sooryavanshi's hands and bat move laterally away from his body to allow him a circular bat swing. He also has a high back lift, similar to his batting hero Brian Lara. Despite the circular swing, his bat comes through straight rather than diagonally. The motion and a snap of the wrists produce hand speed which results in Sooryavanshi's extreme six-hitting ability.

The 61 sixes Sooryavanshi has managed in 17 IPL innings are only three fewer than former England captain Eoin Morgan managed in 75 knocks in the tournament. India great Jasprit Bumrah, Australia's metronome Josh Hazlewood, and New Zealand swinger Trent Boult have all been smacked over the ropes in this year's tournament.

There is often little culture - his most profitable shot is categorised by CricViz as a 'slog' - but the striking is remarkable for its regularity, its uncommon cleanness, and its length. "He gets a full flow and gets everything out of his bat swing but is then able to hold a really consistent base with his feet into the ground, with balance and keeping his head still," Yardy says. "I think there is a unique talent to it. You have got to have an extraordinary gift to do that."

'Why hit a single when you can hit six?' - the making of a teen IPL star. As well as his century in this year's IPL, Sooryavanshi has also made 52 from 17 balls against Chennai Super Kings, a 26-ball 78 against defending champions Royal Challengers Bengaluru, plus four other 30-plus scores in his 10 innings. He is the fifth highest run-scorer in the tournament, while batting with the second highest strike-rate.

"The fact he is so consistent tells me his shot selection is more often than not right," Dasgupta says. "I was talking to a few of the other coaches at [Rajasthan] and obviously he has got the skillset. I was pleasantly surprised when they mentioned he is very sharp and has a good cricket IQ." An astute 'cricket brain' and an extraordinary gift to hit sixes is clearly an alarming prospect for the rest of the game, which must now find a way to respond.

In this year's IPL there has been a slight increase - from 32% to 39% according to CricViz - of bowlers pitching the ball on the stumps to cramp him for room. "A lot of people have started targeting the stumps," Dasgupta says. "If you have a whippy or circular bat swing like his, the downswing is important. When the bat swing does not come down straight and comes down diagonally, there is a chance there will be a gap between bat and pad. That is one area he has to make sure."

Dasgupta also points to a knock of eight from 11 balls against Lucknow Super Giants, which included five tentative dots balls in a row before a sliced high catch offered off left-arm seamer Mohsin Khan. It was one of the few occasions bowlers have tested the teenager with significant swing in this year's tournament. "That's where he was found a little wanting because he doesn't move his feet a lot," says Dasgupta. "He will obviously get better with experience and practice but those are the areas where he might want to look at and work on."

The majority of Sooryavanshi's sixes this year have been hit over the leg side. Despite those struggles, both Dasgupta and Yardy are convinced Sooryavanshi has the talent to successfully play red-ball cricket in the future. Though he averages only 17.25 in eight first-class matches for Bihar, having made his debut aged 12, he has two centuries in under-19 Tests against Australia.

"He is doing things now that players double his age are doing," Yardy says. "You imagine, if he keeps going the way he is, he can play all formats of international cricket." Dasgupta adds: "What people notice are the fours and sixes but he does not hit every ball for a four or six. He does defend as well. He has a good defence as well and a good technique."

But before that and as the only uncapped player in the top 10 of the IPL run-scoring list this year, some are already wondering whether an international call-up could come as soon as this summer. In June, England hosts India for a five-match T20 series. Could Sooryavanshi make the squad of the back-to-back world champions? Usurping incumbent openers Abhishek Sharma, the top-ranked T20 batter in the world and Sanju Samson - India's match-winner in the semi-final and final of this year's World Cup - will be an almighty challenge.

"It is a valid question with the way he has played," Dasgupta says. "The other side of playing international cricket and having a long career is whether you are mentally ready for the rigours. The people in the system have a duty of care to make sure this talent is handled and mentored properly. He should be part of the set-up, not necessarily push him into playing straight away, but keep him in the set-up, let him grow in that environment of international cricket and if possible maybe play one game here."

Similar questions may soon be asked of Yardy, with the likes of Somerset's Thomas Rew, his under-19 skipper, already being touted as a senior England star of the future. "As much as it is great to give young players an opportunity you want to make sure they have a deep confidence they can do it," he says.

"I am sure Sooryavanshi has a very deep confidence in what he is doing now but generally when players go up you don't want them to be thinking 'I don't belong here'." That is not to say he would be afraid of pushing youngsters for high honours. "You see it in all sports," Yardy says. "Max Dowman is playing for Arsenal at 15. Young people are generally developing quicker in all sports now, through higher level facilities and more exposure to coaching - technical, tactical and physical. From a coaching point of view we have to make sure we are not getting caught looking back on how it was 15 years ago, when players were coming through at 19, 20. If players are physically strong enough and mentally can deal with situations it is not a worry with age really."

Sooryavanshi's 175 in India's victory in the Under-19 World Cup final included 15 fours and 15 sixes.