To walk or not to walk?

Nathan McCullum took a stunning catch off Mahela Jayawardene but was denied a wicket Getty Images

Should batsmen walk when they know they're out? This World Cup has thrown up several incidents that have reignited the debate around walking, an issue that gained prominence in the 2003 World Cup semi-final between Australia and Sri Lanka where Adam Gilchrist walked back to the pavilion after an appeal for a catch against him had met with no response from the umpire.

Ricky Ponting, the Australia captain, and Gilchrist's former team-mate, was in a similar situation against Pakistan on Saturday, where a caught-behind appeal against him had been turned down. Unlike Gilchrist, he stayed his ground. The decision was reviewed by Pakistan and he was adjudged out, but all along he knew he had nicked the ball.

"There were no doubts about the nick, I knew I hit it, but as always I wait for the umpire to give me out. That's the way I've always played the game," Ponting said.

The New Zealand-Sri Lanka game in Mumbai involved a controversial decision when what appeared to be clean, and a brilliantly taken, one-handed catch by Nathan McCullum off Mahela Jayawardene was ruled not out by the third umpire Amish Saheba as replays were possibly inconclusive. Jayawardene, once the catch was claimed, stayed his ground and ultimately got the decision in his favour.

"If I felt it was a clean catch, I would have walked," Jayawardene said. "It was a 50-50 thing and it was fair it went to the TV umpire."

However, "it depends upon the person," Ross Taylor, the New Zealand captain for that game, said. "You look at Jacques Kallis. He asks the fielders if they caught it cleanly and he trusts the words of the fielders. You put it up to the batsman to make the decision and at the end of the day you just hope the technology is right and if the technology is not right, well then don't use it."

In India's game against West Indies in Chennai, Sachin Tendulkar, a century away from completing 100 international tons, walked when he inside-edged Ravi Rampaul to the wicketkeeper as Steve Davis, the umpire, shook his head. Darren Sammy, the West Indies captain, was effusive in praising Tendulkar's decision to walk. "It shows the measure of the man," Sammy said. "He is a true gentleman. After 17,000 runs, he could walk. That was brilliant on the part of Sachin."

"It's nice to see people walking but that doesn't happen now I guess," Waqar Younis, the Pakistan coach, said. He added that despite the availability of technology, batsmen could still take a chance with the replays. "There is a system in place now so that you can't get away with it. I mean people still take chances and why not? Jayawardene took a chance and it went the other way."