There is constant debate about which poker site has the best games. In order to shed some light on this question, we poured through our database and analyzed the number of proven winners that are playing on each site at any given time. Here are the results.
For this analysis, we have defined a proven winner as someone who has played at least 50,000 hands and has turned a profit. Anyone who meets this definition is taking at least enough to cover the rake from the other players at the table. Even if there are other players at the table who are better than them, it is difficult to extract the kind of EV from this player that you can from a much weaker player. This group also includes those who are crushing the game, but even the worst players in this group can not be considered a soft seat. You can think of this group as "winning regulars."
To get a good sense of the density of proven winners at the different sites, we took a snapshot of all the players currently playing every 15 minutes. We then checked what percentage of these players fit our "proven winner" definition. The graph below contains the results of this analysis over about a weeks worth of time.
You can see that the percentage of proven winners currently playing is fairly similar across the sites ranging from around 6% to around 18%. Party Poker stands out by consistently having the lowest number of proven winners playing. Cereus is second best. The other sites have very similar numbers.
This doesn't necessarily answer our question though because in on-line poker it is possible to multi-table. To account for that, we looked at the percentage of all the seats at all the tables that were occupied by our same proven winner's group. The results in the chart below are much more interesting.
Poker Stars jumps way above the other sites, consistently having around 30% of it's seats occupied by proven winners. This major difference is likely due to a combination of a relatively strong player pool and the high multi-table limit(24) on Stars. With the ability to play so many tables, the regulars end up filling a large number of open seats.
Party Poker, on the other hand, comes in as our softest site. Even with a moderate multi table limit(12), Party's player pool just does not contain enough proven winners to fill it's games with regulars. It is quite surprising that Party Poker, an established and fairly large site, had less proven winners than a tiny site like Bodog.
One factor that may have influenced the results is that Party Poker allows infrequent name changes for it's players. This may have artificially decreased the number of proven winners since some players may not have qualified due to a recent nickname change. The influence of this would be minor however because any player who plays decent volume would reach the 50k hand qualification level quickly.