Today players are much stronger than he could possibly have been, though. There are a couple of players online of which we can easily say that they are the best players to ever live, and we know from recent advances in AI poker that they still have room to improve. Saying that he is the best player to ever live would be like saying Bobby Fisher or Paul Morphy are the best players to ever live ; it's true in the sense that they were more dominant in their days than anybody else in other eras, but in terms of pure game knowledge it keeps evolving as years pass.