I recently came across a mathematical theorem that I thought was very counter-intuitive. Let’s see if your intuition is better than mine.

Two candidates A and B run against each other. Out of 1000 voters A gets 550 votes and B gets the remaining 450 votes, giving A a 10% winning percentage. Suppose the ballots are counted one at a time. What are the chances that A will be in the lead throughout the ballot count?