At the end of three rounds, when Shiva Thapa and Abhinash Jamwal stood in the middle of the ring grinning at each other, one wouldn’t think that they had spent the last nine minutes furiously trying to hit each other. “It’s how we say hello and ‘good to see you’ to each other,” says Thapa after the prelims of the nationals. One of the marquee clashes at the nationals over the years, Thapa vs Jamwal, is now a staple bout – one that usually would be a final in their weight category but was a prelim at the Indoor stadium of the Gautam Buddha University in Greater Noida on Monday. Clash of generations These bouts at the nationals, once won by the Assamese boxer and now being snatched away by Jamwal, are about as peaceful a transition as it could be from one former champion boxer to a future hopeful. Thapa, a World Championship bronze medallist and one of India’s youngest boxers to be a part of an Olympic Games, is now 32. Jamwal was …