Five-time Fide world chess champion Viswanathan Anand is known for his calm, unassuming manner, but he said it is just a veneer.
"Most of us try to keep a very blank face, but we are not at all calm," he added. "We live through what's on the board very closely. It's (like) an arms race."
Mr Anand, who became India's first grandmaster in 1988, said he takes deep breaths during the game to stay calm. He also finds that it helps to prepare beforehand, by familiarising himself with his opponent's style.
The 47-year-old was at Overseas Family School (OFS) yesterday for simultaneous exhibition chess games against 50 students.
The event, attended by about 400 students aged six to 16, was supported by the Singapore Chess Federation (SCF). Some students were selected by the SCF from OFS, as well as from other schools here.
To ensure that people of all abilities had the chance to play against Mr Anand, half of the players were selected by ballot.
The final score was 48-2 in Mr Anand's favour. Two of SCF's five chosen players - Lee Jun Wei, 15, and Ethan Poh, 12 - beat Mr Anand.
Said Jun Wei: "I'm quite relieved. I feel that Anand gave me a chance."
Said Mr Anand: "The children were quite good. (There is) some progress to be made, but the better ones show a lot of promise.
"The most important thing you can do in chess is to play against another chess player, and not get into this habit of interacting only with the computer."
Mr Anand, who learnt to play chess at the age of six, said parents should not be too pushy. "Chess should fascinate (the child). I don't think you can push them (into it)."
One day, Singapore might have its own world chess champion too, he said.
"In Norway, nobody played chess 10 years ago and now suddenly, it's the rage... Same thing happened in India," Mr Anand said.
OFS academic director Patrick Keenan said: "Chess is an important part of our intellectual development programme, and is integrated into our curriculum in both kindergarten and elementary school.
"To have someone of Mr Anand's calibre was a real bonus, and this event should do a lot to promote chess in Singapore schools."