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Cracking the Scratch Lottery Code

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Re: Cracking the Scratch Lottery Code

#61

Post by ajju »

nfriedly wrote: post #56
Xk wrote: post #2

In some states, the lottery accounts for more than 5 percent of education funding. Am I the only one who finds this ironic? Edit: Except, of course, for those who learn to predict 19 of 20 tickets correctly.

To make matters worse, my understanding is that when the state receives money from the lottery for the schools, that money does in fact go to the schools... and then an equivalent amount of money comes out of the school's budget and goes into the state's general budget. So, for example: if the school budget for the year is $5 million, and lottery brings in $1 million for the school, the school doesn't get $6 million…

Ha! So the lottery is paying for everything but education.

Re: Cracking the Scratch Lottery Code

#62

Post by ynniv »

aamar wrote: post #51
ynniv wrote: post #48

Earlier quoted context omitted.

The solution is straightforward: generate truly random boards, evaluate them, and then use the set that fits your payout profile. The problem is that these boards will lack the enticing hooks that keep folks coming back. The complete solution is to also discard boards that are not enticing enough. The result will have fewer artificial patterns like the ones used in the article to determine winners.

That procedure is vulnerable to the same issues mentioned in the article. Let's say you design a game that has outcomes Lose, Near-Miss, Win, and Invalid (tickets that must be suppressed, e.g. multiple wins). Then, imagine a rare, salient pattern, like 3 singletons in a baited-hook row. That might be an extremely rare occurrence in the overall lot of random boards, but it might still occur disproportionately in, or i…

this is a game design issue

Only if the "game design" purposely used a limited pool of numbers for the visible and hidden boards. If there was no guarantee that a number would appear 1.9 times, then seeing singleton numbers wouldn't be a predictor.

My guess is that the restricted number pool was used as a means of easily mapping a number (the number on the back of the card) onto a playing board. Anyone interested in the why and how of this should look at The Wizard of Odds[1]. If the number on the card was used to seed a PRNG which then produced a lot more data, there could be a more sophisticated board generator that doesn't need to take such compromising shortcuts.

So in a sense, the culprit is game design in that rules were created to allow for certain percentages of Loses, Near Wins, and Wins. But there is no reason to mix output control into game design. My suggestion is to make the game rules with no regard to controlling output. Instead, evaluate the generated boards and keep/drop them to control the output.

[1 | http://wizardofodds.com/slots/]

Re: Cracking the Scratch Lottery Code

#64

Post by MichaelApproved »

It seems that a large part of the problem (aside from flawed algorithm) is that they allow people to pick the tickets they want to purchase. If they required people to buy the tickets in order they're dispensed from the roll it would bring the abuse down dramatically.

Even if you were able to crack the code you'd have to wait for others to buy the losers before a winning ticket would show up. The flaw in this would be if the store selling the tickets was be in on the scam. They'd be able to sell a bunch of losers and pull any winners as soon as it was their turn to dispense. But as with most crimes, the more people involved in it, the harder it is to keep quiet about it and pull it off.

Re: Cracking the Scratch Lottery Code

#65

Post by asr »

I excitedly went to the Virginia lottery website, thinking maybe I could find a game or two possibly vulnerable to something like this and then buy a few tickets for the fun of seeing if this can still be done...

But manufacturers appear to have dealt with this by getting rid of "baited hooks"--every number on a card is under a surface that has to be scratched off.

I guess they lose the allure of letting people say "I want to buy a card with lots of 7s because that's my lucky number" but it's a simple and effective fix. Oh well, guess I'll have to get rich through hard work :)

Re: Cracking the Scratch Lottery Code

#67

Post by amalcon »

golgo13 wrote: post #14

In Canada, are you able to say, "I don't want this one" until you get a potential winner? Here in Texas, you cannot pick your ticket. When you buy a ticket, you get whatever the cashier gives you or whatever the machine spits out. Or is the guy simply not wasting time scratching off the losers? I still don't see how this could be profitable since most games have 1:5 odds, including break even prizes.

It would not work, except that some lotteries have been trying to get creative with marketing. They want to give people an illusion of control, hence letting them choose between several "different" tickets. This is the "baited hook" they mention.

In theory, the tickets are not actually visibly different. In practice, apparently they are, just not in entirely obvious ways.

Re: Cracking the Scratch Lottery Code

#68

Post by brown9-2 »

Prisen wrote: post #50
lkozma wrote: post #11

I find it strange that they don't use some true random source in generating the tickets. I'm also surprised the article finds this obvious. "Of course, it would be really nice if the computer could just spit out random digits. But that’s not possible, since the lottery corporation needs to control the number of winning tickets" Surely the lottery could quantify uncertainties and set up a system where the probability…

They probably have to specify exactly what percentage of income is given out in winnings. Not to protect the lottery company, but to protect lottery buyers.

Yes exactly. Imagine the scandal that would be had if someone ran a lottery that was impossible to win.

Re: Cracking the Scratch Lottery Code

#69

Post by aamar »

ynniv wrote: post #62
aamar wrote: post #51

Earlier quoted context omitted.

That procedure is vulnerable to the same issues mentioned in the article. Let's say you design a game that has outcomes Lose, Near-Miss, Win, and Invalid (tickets that must be suppressed, e.g. multiple wins). Then, imagine a rare, salient pattern, like 3 singletons in a baited-hook row. That might be an extremely rare occurrence in the overall lot of random boards, but it might still occur disproportionately in, or i…

this is a game design issue Only if the "game design" purposely used a limited pool of numbers for the visible and hidden boards. If there was no guarantee that a number would appear 1.9 times, then seeing singleton numbers wouldn't be a predictor. My guess is that the restricted number pool was used as a means of easily mapping a number (the number on the back of the card) onto a playing board. Anyone interested in…

If there was no guarantee that a number would appear 1.9 times, then seeing singleton numbers wouldn't be a predictor.

Let's say there's no such demand, and the boards are generated truly randomly and neutrally. If visible-quality X is disproportionately correlated with invisible-quality "Win" then the game is already flawed; this may emerge naturally from the Win conditions and from the game design decision of what is shown in the baited-hook. If the output is controlled post-generation to increase the proportion of Win cards and Near-Win cards vs. Lose and Invalid cards, then the statistical correlation may be greatly increased.

Simplified example: Scratcher with two numbers 0-4: one bait, one hidden, pays if sum is 5 or 6. If everything is fair and truly random, the odds of winning are, 0 showing: 0%, 1 showing: 20%, 2-4 showing: 40%. Already a bad game, but now the game designers want to eliminate cards with sums of 7 or 8 because this confuses people, (not minding that they're changing overall odds of winning), so they block those Invalid cards from shipping without blocking anything else. That gives:

    0 1 2 3 4
  0 - - - - - 
  1 - - - - W
  2 - - - W W
  3 - - W W I
  4 - W W I I
The new odds of a given ticket, given the visible number, are: 0: 0%, 1: 20%, 2: 40%, 3: 50%, 4: 67%. The point here is that now a 4-showing-card is >3x as good as a 1-showing card, when it used to be only 2x as good, and it might now have positive expected return.

Re: Cracking the Scratch Lottery Code

#70

Post by Duff »

I'll open myself up to scorn by admitting that I buy these things often. You don't get to select your tickets in NY, they are ripped off one at a time on a roll that is in a locked container.

The most obvious vulnerability here is clerks and convenience store owners who unroll the tickets and hand out the loser tickets to customers. That risk is mitigated by the craziness of lotto addicts, who won't accept a ticket that doesn't come off of the roll.

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