Eighteen-year-old Prithvi Shaw's method of driving through the off side defies the coaching manual. Instead of transferring his weight forward and meeting the pitch of the ball, he usually hangs back with his back leg often falling to the leg side. Karnataka veteran Vinay Kumar exploited this technical weakness when he had him caught at slips with an outswinger during his hat-trick in the Ranji Trophy quarter-final against Mumbai in Nagpur last year.

In the Under-19 World Cup final against Australia at Mount Maunganui in February, Shaw kept reaching out for full away-swingers outside off. Seamer Zak Evans beat his outside edge twice before Shaw threw his hands in the corridor and squeezed two other balls to the off side in the second over of India's chase of 217. After Evans threatened the outside edge, Will Sutherland found it with a perfectly pitched away-swinger. Shaw dragged his back leg down the leg side and his head fell over as he shaped to drive away from the body.

Even on Sunday, when he was playing for India A against South Africa A at the Chinnaswamy Stadium, Shaw was initially tentative outside off. A play and miss here. A stab past the slip cordon there. Seeing the hard, new ball move off the seam, Shaw then opted to shelve the drive in the early exchanges and later nailed them in the arc between point and mid-off once the ball became softer.

"I think [in] the morning session that ball moves here. If you play [out] that first hour, it becomes easier and the ball comes on," Shaw said after play on day two. "Taking the morning session out [is important] and the scoreboard kept moving."

Shaw admitted that he was working on maintaining a stable base, particularly while driving the ball, but wasn't too bothered with his back leg collapsing down the leg side.

"In the practice sessions, I tried to get the back foot across [and not down leg] but it's not happening," Shaw said. "But Rahul [Dravid] sir said, 'it's fine if you're doing that and you're scoring runs'. It's not affecting me while scoring runs. I know it's a mistake but I am still comfortable with my batting."

The drives weren't perfect but they were easy on the eye, leaving a sparse Sunday crowd in Bengaluru chanting "Prithvi! Prithvi! Prithvi!" and the South Africans scratching their heads. Duanne Olivier, Beuran Hendricks, Malusi Siboto, Shaun von Berg, Dane Piedt and Senuran Muthusamy were all crunched through the covers. Just when Shaw seemed set for much more, he misread the turn of an offbreak from Piedt and was bowled through the gate for 136 off 196 balls.

However, his senior opening partner, Mayank Agarwal, who is likely to be in contention for national selection alongside Shaw, kicked on to an unbeaten double-century on the second day. This follows a record domestic season in 2017-18, in which he tallied 2141 runs for Karnataka, and a productive maiden stint with India A in England, where he cracked three hundreds in the team's run to the one-day tri-series crown.

"Me and Mayank have a good understanding while batting," Shaw said. "We've now played a lot together in the India A series in England and we're continuing it here. It's (the success) because of how we talk on the field while batting and whenever he does some mistake, I'll be the one who tells him that. It's very important when he have an understanding and to know how to build an innings. This is what kept us going today. Mayank's double-hundred is a great knock and I think this is the best I've seen him bat. He is still going on and I want him to make a bigger score tomorrow."

Shaw gushed when asked about sharing the dressing room with M Vijay and Ajinkya Rahane in the four-dayer against England Lions in Worcester last month. Is he closer to sharing the dressing room with them in the national side? For a definitive answer, you needed to be a fly on the wall when his coach Dravid and chief selector MSK Prasad were chatting after an utterly dominant batting day.

Deivarayan Muthu is a sub-editor at ESPNcricinfo