Conversation so far:
What can you tell me about walking and discipline?
Cricket has for many years debated whether batsmen should "walk".
What did he say in regards to his stance on batsmen?
Gilchrist reignited this debate by walking during a high-profile match, the 2003 World Cup semi-final against Sri Lanka.
What happened in the 2003 world cup match?
after the umpire ruled him to be not out.
He has since proclaimed himself to be "a walker".
Did anyone oppose the decision?
Gilchrist's actions have sparked debate amongst current and former players and umpires.
Did any rules change based on his protesting?
CANNOTANSWER.

Question: What did the former players debate?
Self-contained rewrite: What did the former cricket players debate?