## Luck or knowledge?

Joan Ginther has won the Texas lottery four times. First, she won \$5.4 million, then a decade later, she won \$2million, then two years later \$3million and in the summer of 2010, she hit a \$10million jackpot. The odds of this has been calculated at one in eighteen septillion and luck like this could only come once every quadrillion years.

According to Forbes, the residents of Bishop, Texas, seem to believe God was behind it all. The Texas Lottery Commission told Mr Rich that Ms Ginther must have been ‘born under a lucky star’, and that they donâ€™t suspect foul play.

Harper’s reporter Nathanial Rich recently wrote an article about Ms Ginther, which calls the the validity of her ‘luck’ into question. First, he points out, Ms Ginther is a former math professor with a PhD from Stanford University specialising in statistics.

More at Daily Mail.

[Edited Saturday] In comments, C Ryan King points to the original article at Harper’s and Bill Jefferys to Wired.

1. Ian Fellows says:

The only lottery winner to actually earn her money?

2. John says:

There must be some non-randomness to draws using those standard ball and air blowing machines. One of the first things is that the balls are all often loaded in a particular order (usually sequential). Then they all can’t be the same weight, which would impact relative landing positions. And, it’s entirely possible that the relative selection of balls is important (but does Texas give the selection sequence?). In any event, she’s probably analyzed the prior lotteries and based her bet on slight skews in the probabilities. Compound that with betting all around that skew and she may be just doing well enough?

One thing that has been missing from all of the reports of how well she’s doing is a report on how many tickets she buys.

• Jeremy Miles says:

It was scratchcards, not draws. There was an article in ‘Wired’ a few months ago about someone who had worked out some of the patters.

• Jeremy Miles says:

Referenced further down.

• AlanH says:

Even tho is was scratchcard instead of balls, ball can and should be the same weight. Get a bunch of them, have the numbers printed on, sort them by weight, assemble complete sets of same weight.

3. John says:

In fact, I was just looking at the stats for the Canada lotto 6/49 (http://www.lotto649stats.com). I looked first at most frequent numbers by order in sequence and it implied that there are peaks where it’s best to space out the numbers you select fairly evenly. Then I looked at the stats for the most frequently selected 4 numbers and there it is… they’re generally spaced out pretty evenly. It’s clearly not entirely random. Now, if I had access to the whole database I might be able to extract lots more information. I’m not suggesting I could get the odds in my favour or anything ludicrous like that, just down from random. She may have just put a lot of effort into it and bought a lot of tickets. Maybe her odds were more like 1:10000…. maybe she’s one of 10,000 people in Texas doing this?

4. Jeremy Miles says:

Samuel Goldwyn was supposed to have said “The harder I work, the luckier I get”. Sounds a bit like this.

5. C Ryan King says:

Although paywalled, harpers does provide online access (http://harpers.org/archive/2011/08/0083561).

6. The article mentioned the statistician in Canada, but didn’t give information. Here’s the relevant link:

http://www.wired.com/magazine/2011/01/ff_lottery/all/1

Mohan Srivastava is the gentle person who figured this particular thing out.

7. The article says that she has moved from Texas to Las Vegas. Either she is a gambling addict, or she has a scheme for some bigger payoffs.

8. C Ryan King says:

Or maybe NV has kind tax laws for her.

• I can’t imagine what. There’s no income tax in Texas.

9. [...] so-&-so, while the event of interest does not.) (I wrote this post before Alex pointed out the four-time lottery winner in Texas, whose “luck” seems more related with the imperfections of the lottery [...]