So jackpotchasing's post made me want to look up something indirectly related, and in that I found something that I believe people here may find interesting so I wanted to post it. (This is not related to his post though).
From an article:
Actually, the odds were better than that. Scratch-off prizes are not randomly distributed. Lotteries use a system of “pools” to create a fairly even distribution of prizes, as described in Indiana and Massachusetts reports.
“Most lotteries want prizes to be evenly spread throughout the game and not back-to-back, and our job is to securely and as randomly as possible accomplish this for the lotteries,” said Joe Bennett, vice president of game development for Scientific Games, which prints scratch-offs for every state lottery but Michigan’s.
Strictly speaking, “evenly spread” and “randomly as possible” are contradictory. So lotteries, in a way, divide the game into sections, then randomize each section. It’s like shuffling three decks of cards separately, instead of shuffling them together.
And then from this: https://www.hoosierlottery.com/media/2781819/consumer_protection_final.pdf
To ensure the even distribution of winning tickets, instant games are produced in segments known as “pools”. Over time, the concept of pool has evolved to represent the approach used by lotteries to ensure the even distribution of winning tickets throughout a game.
As is the practice in the lottery industry, the specifications as to the types and quantities of prizes for a game are described as the “Prize Structure”. The Prize Structure for a game specifies how many of each type of prize are to be included in each pool. The number of tickets in a pool is defined in the Prize Structure as well. Depending upon the ticket manufacturer, the lottery and the game, a pool may contain 120,000, 240,000 or 250,000 tickets or some other amount of tickets.
By specifying the types and quantities of prizes to be included in each pool, the Lottery and the ticket manufacturer ensure the even distribution of winning tickets throughout their games. Depending upon the value of the top prize and other large prizes in a game, it may not be possible to include one of each of these prizes in each pool of tickets. In these situations, the Lottery and the ticket manufacture agree that these prizes will be allocated over a multiple number of pools, maintaining the concept of an even distribution of prizes across the game.
Another element that is used to ensure the even distribution of prizes throughout each game is the use of Guaranteed Low End Prizes Structures (GLEPS). GLEPS is a process for specifying that each pack of tickets contain a specific assortment of small prizes that has an equivalent value.
There are usually between 3 and 5 specific GLEPS patterns used in programing an instant ticket game, though other amounts can be established for specific games. Each pattern contains a GTECH Indiana Consumer Protection different combination of small prizes that total to an equivalent (or near equivalent) value of small prizes. The GLEPS patterns are specified as part of the Prize Structure for each game. The Lottery can be assured that the distribution of prizes across tickets, regardless of strip, pack, lot, shipping box, or pool location, for any game is randomly distributed according to the game requirements established by the Working Papers and Client Standards documents.
Accounting Checks of Randomization
All games are subject to checks during programming and production by separate members of the software team and quality control staff to verify that the specifications included in the Working Papers for each game have been met and that the distribution of the winning tickets is random throughout the game. In addition, an internationally recognized accounting firm independently audits the programing of each game. They also confirm that the specifications included in the Working Papers have been met and that the distribution of the prizes is random throughout each game. As is the current practice, all instant ticket suppliers will be required to deliver an audit report prepared by an independent firm skilled in this activity to GTECH Indiana.
This post is long enough, so there is more in another doc at: http://www.masslottery.com/lib/downloads/procurement/awarded/RFR_1211_Instant_Ticket_2012%20_1_.pdf
Specifically I thought sections 1.7.7, 1.7.8, and 1.9 were notable and worth reading.