This comes from the fact that the first run of six 9's in the digits of pi comes much sooner than expected: http://www.geom.uiuc.edu/~huberty/math5337/groupe/digits.htm... search for 999999 - you'll see it's only 10 lines down. When discovered, this caused a lot of people to conclude that the digits were not random. Of course, with 5 trillion digits now calculated, there is still no bias found toward any pattern. So it is very hard to tell!