Need help! My friend thinks coin flips are 50-50! Alright, I've been trying to convince my friend that the outcomes of a coin flip x times in a row affects the x+1'th time. If you flip a coin 4 times and they are all heads, the 5th time is more likely to be a tail because if the coin is even, over time there should be as many tails as there are heads. I even tried to prove it to him using math: P(5 heads in a row) = .5^5 = 0.03125 P(4 heads in a row) = .5^4 = 0.0625 Which directly translates into: 5 heads in a row is less likely to happen than just 4 heads in a row so if you flip a coin and get 4 heads, the 5th time is more likely to be a tail. My friend just doesn't understand this, he's saying that even when I'm calculating the probabilities, I'm using .5 for each flip so the probability should be .5 every time, but he's obviously wrong, because the probabilities are different! Please help me convince him that my way is right...after all why does he think when they do coin flips, they do best out of 3 times???