Is the problem with the word "pattern" rather than, say, "structure"? Something which is random can have an underlying structure which you can use to make predictions. I roll a d6, I'm not going to predict that the roll is 13. I draw my opening hand in Dominion, I know that on a typical board there are only 4 different hands I might see and two of them are more likely than the other two. I look at the stock market today, I can take a guess at where it will be tomorrow. I can never be 100% certain about the outcome of any of those events, but I know *something* about them that lets me make predictions, and if I observe such events a lot of times then, on average, I know what those observations will look like.