The first-ever cricket world cup for the visually impaired opened in New Delhi on Tuesday amid the rattle of plastic balls, noisy midfield action and under-arm bowling. Teams from seven elite cricketing nations - England, Australia, New Zealand, South Africa, India, Pakistan and Sri Lanka - are taking part in the 10-day event, the first international tournament of its kind. Not all players are blind though. Rules allow teams to field three players who are partially blind (20 per cent vision) and four who are partially-sighted (40 per cent vision), along with four players who are totally blind.

The only concession afforded to the totally blind is that they can take the help of runners while batting. But they are required to bowl at least 16 of the allotted 40 overs. Batsmen and fielders rely wholly on the noise emanating from pebble-filled plastic balls.

Novel tactics and strategies are part of the game. The New Zealanders posted three totally blind players near the bat at silly point, instead of the usual one, to cover the offside area.

"It's a masterstroke," an admiring supporter said. "These players may not be as effective in the deep. Here they form a wall to stop the off-side strokes."

The three players are well protected by helmets and chest and abdomen guards, although serious injury is ruled out since the balls weigh only 100 grammes.

The rules are the same, except that the bowler asks the batsman "ready?" and bowls under-arm only after the batsman has replied "yes". The game is supervised by sighted umpires. The difference becomes evident when the game halts suddenly as happened when a roadside band began playing popular Indian film music at a marriage ceremony outside the ground. With the background noise, none of the players could hear the sound of the approaching ball.