Doing the Microsoft Shuffle: Algorithm Fail in Browser Ballot

“But this wasn’t a simple case of Internet Explorer
showing up more in the first position. The non-randomness was
pronounced, but more complicated. For example, Chrome was more
likely to show up in one of the first 3 positions. And Internet
Explorer showed up 50% of the time in the last position. This has
lead to various theories, made on the likely mistaken theory that
this is an intentional non-randomness. Does Microsoft have secret
research showing that the 5th position is actually chosen more
often? Is the Internet Explorer random number generator not random?
There were also comments asserting that the tests proved nothing,
and the results were just chance, and others saying that the
results are expected to be non-random because computers can only
make pseudo-random numbers, not genuinely random numbers.

“Maybe there was cogent technical analysis of this issue posted
someplace, but if there was, I could not find it. So I’m
providing my own analysis here, a little statistics and a little
algorithms 101. I’ll tell you what went wrong, and how
Microsoft can fix it. In the end it is a rookie mistake in the
code, but it is an interesting mistake that we can learn from, so
I’ll examine it in some depth.”

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