Suppose there are 4096 actively-managed mutual funds. Suppose also that the markets are perfectly efficient, so it is not possible to beat the market by 'skill', only by luck.
Let's say that a fund has a 50/50 chance of beating its benchmark index every year. How many funds would you expect to beat the index every year for the past 10 years straight?
Bonus question: if you invest your money into one of these funds that beat the benchmark every year for 10 years, what is your chance of beating the benchmark next year?