Rishi has also made his mark in international sudoku competitions, finishing as runner-up twice at the Brand's International Sudoku Competition in Bangkok, Thailand, in 2011 and 2012.
Additionally, he won the Times UK National Sudoku Championship in 2012.
Notably, Rishi was the first Indian to qualify for the World Puzzle Federation's Sudoku Grand Prix, finishing in the top 10 globally and securing 9th place in 2014.
He further improved his standing in 2015, achieving a career-best 7th place at the Grand Prix held in Sofia, Bulgaria.
The 2015 World Sudoku Championship was Rishi's final competition before his retirement.