[AaronBrown]

There are three distinct issues.

First is whether the hands you get in on-line poker are distributed precisely as a theoretically perfect shuffle. The more transparent sites publish enough details of their methodology to reassure people that it should be almost perfect, and some publish sample outcomes which always conform to statistical expectation.

However, if I were hired as a statistical auditor, I would concentrate on the outputs (the cards dealt) not the inputs (the theoretical perfection of the random number generator). I wouldn't just look at the unconditional distribution of pocket and board cards, I would look at what matters to poker players, the distribution of hand strength; particularly the correlations between different hands at the same table and the same player in different hands. There are a lot of steps between random number generation and hand output that could have bugs. To my knowledge, no one has ever done anything like this. I'd also look hard to see if any player enjoyed superior luck, more than could be explained by random chance. This could be an insider or someone who figured out how to hack the site.

So, on this point I would say there is some published information, but less than a skeptical person would demand.

The next point is whether the sites deliberately skew the distributions, whether to push up the rake or attract players. I don't agree with the "it's only a few pennies in rake" argument. If you push up revenue by 1% while keeping costs constant, you can push up profit by a much larger percentage. Moreover, a manager under pressure to hit some target might well compromise the integrity of the business to make a few dollars, we've certainly seen enough of that over the last few years.

No site publishes anything that would refute this. It wouldn't matter if they did, because if you don't trust them to deal the cards fairly, why would you trust their reported statistics? Even if an independent audit firm did the analysis, it's hard to know what they would look for. You could easily rig things but keep the overall distribution of cards as expected by chance.

So on this issue, I'd say there is no information and not likely to be information. Trusting people will trust the sites, suspicious people won't.

While either of those types of non-randomness would bother me as a player, neither one is unfair. Assuming they're too subtle to notice, they wouldn't affect play much. So they're only theoretical problems, even if they exist.

The third kind of rigging is the really worrying kind. The site could have hired players, or bots, to win people's money by cheating. But here there is no evidence that could be produced. The cards and hands could be perfectly random, but the bot could know what they were. An auditor might discover that some players seemed much better than others, but unless she contacted individuals, she couldn't prove it was anything more than skill differences.

The bottom line is that people who believe the sites are rigged will never see evidence to disprove that. On the other hand, there's never been a shred of evidence to prove that any site is rigged in any of the three ways.