As has been stated, flip the coin an odd number of times to avoid a tie. A collection of N honest 50:50 results will have a statistical error of sqrt(N). 100 flips wll have a 10% error rate. 10,000 flips will have a 1% error rate.

Make a decision based on even or odd. See how many people attended a racetrack that day. There is your answer, such as it is.

Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz3.pdf