Law of averages

The "law of averages" is an expression which proports to predict events based on statistics; however, this expectation of probability is based on an improper understanding of statistics.

This "law" predicts that statistical events will occur exactly as the "odds" predict. Or, whatever should happen "on average" WILL happen.

For example, if you toss a coin 100 times, it WILL come up heads 50 times and tails 50 times. Or if the odds of winning a prize are one in a million and a million people play, one person (and only one person) will win.