Random events can be misleading. Flip a coin. It has a 50% chance of landing heads and 50% tails. Now suppose it has landed heads 10 times in a row. What are the chances it will land heads up on the next toss? If it is truly an unbiased coin, the odds for a heads up will be 50%. Past events have no effect on future events. But what are the odds that a coin will land heads up ten times in a row?
The chart below shows a plot generated from a random number generation program, Drunkard's Walk. Try running the program Drunkard's Walk yourself and see what kind of trends you can generate from a random process. Enter any number in cell B8 (Count). Press return. Each plotted point is the sum of the previous plotted point plus the random assignment of a one or a minus one. Are there trends? Does it always look random?