From the Powerball.com FAQ page:
HOW COME THE ONLY JACKPOT WINNERS ARE FROM THE [EAST - WEST - NORTH - SOUTH - CITIES - RURAL AREAS]?
HOW COME ONLY [WHITE, BLACK, TALL, SKINNY, YOUNG, OLD] PEOPLE WIN?
Powerball is a random game that knows nothing about who buys a ticket or where a ticket is purchased. There really is no white/black/old/young/rich/poor, etc.] button on the machine. If one draws a box around some group of players (eg., state border, hair color, shoe size), then that group of players will win in proportion to their play. If the defined group buys 10% of the tickets, then they will win 10% of the prizes - on average and over a reasonable period of time. But that does NOT mean that you have a better chance of winning in a bigger box - you then just have more folks to play against. The Law of Large numbers explains how random expectations become truer as the number of occurrences increases. So, if players in a particular group buy 8.6754% of the tickets, then we will find, if the number of occurrences (prizes awarded) are large enough, that those players win 8.6754% of the prizes. This is definitely true for the low-tier prizes where there are large numbers of winners. With 12 to 15 jackpot winners in a year, we would expect that these percentages can get out of sync with sales from time to time, but as the number of jackpot winners continues to increase, we will find that the percentage numbers move closer and closer to being the same number. Try this experiment. Flip a coin four times. You might get 75% heads - or even 100%. You would not expect to get excited about that. With only ten flips, it can happen. But then flip it 1,000 times (no cheating). You will come much closer to the statistical expectation of 50% heads. If you hit 75% heads after 1,000 flips, then something is wrong. It really does NOT make any difference where you buy your ticket. It is you a against the draw machine.
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I wish a lot more people here would visit that page. Instead of pure conjecture just go get the facts.
You have to be on the internet to get to LP and it doesn't take a whole lot more effort to get to the PB FAQ page.
A lot of things pondered here are answered there.
Those who run the lotteries love it when players look for consistency in something that's designed not to have any. So many systems, so many theories, so few jackpot winners.
There is one and only one 'proven' system, and that is to book the action. No matter the game, let the players pick their own losers.