system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 - How can the concepts of mean reversion and independent events coexist?

I flip a coin 4 times and they all landed on heads. I'm about to flip a coin for the 5th time.

Independent event theory would suggest that my probability of getting heads or tails is still 50 50 for this flip.

However, according to mean reversion, the average number of heads should tend towards 0.5 and hence isn't the probability of tails higher?
gpt
Mean reversion doesn't require the probability of tails on any individual flip to become higher. Instead, it's the number of flips that causes the average to tend towards 0.5.

Suppose you've flipped your 4 heads. Rather than thinking about the next flip, think about the next 100 flips. You'd expect to get something very close to 50 heads and 50 tails, which makes your initial 4 extra heads much less significant. The overall average will be something close to 54/104, or about 52%.