Hi, how would you go about calculating the probability that on any given day (24 hours) you toss heads say 20 times in a row. That is, let's say you continuously throw a coin, one toss per second. What's the probability that on a specific day there was one run of 20 heads in a row? I'm thinking I need to use Poisson distribution formula, but then I need the average and the definition of the event. Both are tricky. I can't arbitrarily define events by dividing 86400 by 20, because what if there are 5 heads on the last 5 tosses of one event and 15 heads of the first tosses of the next event? That would constitute as 20 heads in a row, but that would not constitue the success by definition of the event. Finding the mean seems to be even more challenging. How do I find out how many occurences of 20 heads in a row happen on average? I mean I can find the probability of 20 heads out of whatever number of trials by using the binomial distribution, but that doesn't give me "in a row". If I simply use 2 to the power of 20, then I limit myself to specific 20 tosses only, not any set of 20 out of 86400. Any suggestions? Thank you in advance.