If you were to make a substantial bet on winning four coin flips in a row, you'd have to win a 50-50 chance each of four straight times. The probability of success is 1/16. That's very lucky. It isn't relevant that each individual coin flip is an even chance. What's hard is winning several in a row. Maybe the hang-up is on the word "lucky." We can put it a different way. If another team should have happened to be the #2, #3, and #1 lottery seeds in those years, they would have been 14 times as likely to get worse picks than to do as well as the Sixers did. Call it good luck or bad luck, but it's a mathematical fact.