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MIT staff blogger Matt McGann '00

Bringing Down the (Lottery) House by Matt McGann '00

Like the movie '21,' but with scratch tickets.

If you enjoyed the story of the MIT Blackjack Team — the movie “21” and/or the book on which it was based, Ben Mezrich’s “Bringing Down the House” — then you’ll really enjoy this recent story from WIRED.

The story centers on MIT alum Mohan Srivastava ’79. Srivastava, a Course 12 grad who later wrote the textbook on applied geostatistics, now runs his own consulting company in Toronto, Ontario, Canada. One day, the story goes, he won $3 on a “tic-tac-toe” scratch lottery ticket he received as a gift, and started thinking about how the algorithm behind the tickets worked.

“I remember telling myself that the Ontario Lottery is a multibillion-dollar-a-year business,” he says. “They must know what they’re doing, right?”

That night, however, he realized that the voice was right: The tic-tac-toe lottery was seriously flawed. It took a few hours of studying his tickets and some statistical sleuthing, but he discovered a defect in the game: The visible numbers turned out to reveal essential information about the digits hidden under the latex coating. Nothing needed to be scratched off—-the ticket could be cracked if you knew the secret code.

See if you can figure out the “secret code” within the unscratched Ontario Lottery ticket pictured here. Here’s a hint: this is a winning ticket, and the tic-tac-toe occurs in the third game down in the right-hand column. When you give up, check out Srivastava’s method.

So, did Srivastava take the lottery for millions, like the MIT Blackjack Team took Las Vegas for millions?

“I remember thinking, I’m gonna be rich! I’m gonna plunder the lottery!” he says. However, these grandiose dreams soon gave way to more practical concerns. “Once I worked out how much money I could make if this was my full-time job, I got a lot less excited,” Srivastava says. “I’d have to travel from store to store and spend 45 seconds cracking each card. I estimated that I could expect to make about $600 a day. That’s not bad. But to be honest, I make more as a consultant, and I find consulting to be a lot more interesting than scratch lottery tickets.”

Instead of secretly plundering the game, he decided to go to the Ontario Lottery and Gaming Corporation. Srivastava thought its top officials might want to know about his discovery. Who knows, maybe they’d even hire him to give them statistical advice. “People often assume that I must be some extremely moral person because I didn’t take advantage of the lottery,” he says. “I can assure you that that’s not the case. I’d simply done the math and concluded that beating the game wasn’t worth my time.”

Maybe there’s something to be said for the old saying, “The Lottery is a tax on people who are bad at math.”

15 responses to “Bringing Down the (Lottery) House”

  1. William'15? says:

    There seems to be a few repeated digits in the card shown in this post. Is that a coincidence, or does it point towards something? I’ll try solving it as well!

  2. William'15? says:

    *Edit from previous post* There seems to be a few repeated numbers in the card shown in this post (e.g. 11, which appears 3 times and 35 which appears 2 times). Is that a coincidence, or does it point towards something? I’ll try solving it as well!

  3. William'15? says:

    After manually counting the number of times a particular number appears in the card, the maximum number of times a particular number appears on the card appears to be three times only…

  4. William'15? says:

    Following Matt’s hint, in the third square in the right-hand column, the first row happens to have numbers that appeared three times in all the numbered squares (i.e. 31, 11, 20), while the second row happens to have numbers that appeared only once in all the numbered squares (i.e. 24, 12, 29). Does this mean that the first two rows in the third square of the right-hand column happens to be tic-tac-toes?

  5. William'15? says:

    Btw, to facilitate those who are attempting to solve this problem, here is a list of the numbers used in the card (left-hand column), and the number of times each number in the left-hand column appears in the card (right-hand column)
    23 2
    31 3
    25 2
    38 3
    11 3
    09 2
    19 3
    26 2
    05 2
    02 1
    35 3
    32 2
    20 3
    17 3
    03 2
    33 3
    34 2
    06 1
    16 2
    22 2
    36 2
    04 2
    37 2
    15 3
    27 1
    18 2
    01 1
    21 1
    10 1
    24 1
    12 1
    29 1
    13 1
    28 1
    07 2
    14 1
    36 1
    39 1
    30 1

  6. Nice !!

    “The Lottery is a tax on people who are bad at math.”

    :D

  7. Edward'15? says:

    Amazing@.@ Like I always say… Math is the Path!!

  8. Maria says:

    *When* I give up?

    …you’d think that’d be an “if” smile

  9. Anonymous says:

    Is man vs machine jeopardy today?

    I know MIT chipped in for this great challenge

    http://www-03.ibm.com/press/us/en/presskit/27297.wss

  10. I got excited when I saw my home town represented in this post =D

    Amazing stuff!

    I was going to go out to get a ticket (well, with my parents since I can’t buy them alone), analyze them in the store, buy it, scratch it and try it out….
    but then I read:

    Scratch off the latex. You’ve got a winner! Not surprisingly, after Srivastava alerted the Ontario Lottery to his technique, the game was pulled from stores.

    Oh well. Haha

  11. To add to my post above, I watched an interview of Mohan Srivastava and something caught my ear:

    When the OLG called him to discuss this issue, he smiled and said that he remembered seeing the exact time on his called display when the OLG called him.

    This man definitely loves numbers =D

    I should tell my grandmother about Mohan because she loves to play the scratch card games for fun. Maybe she’ll get a kick out of this.

    Go MIT grads! smile

  12. Ryan says:

    Really amazing !!

  13. MG '15 says:

    Bringing Down the House inspired me to apply to MIT smile

    awesome story – makes you wonder how so many people can think math is pointless