Interesting

It's all about the maths:

Rubin plays against lawyers and doctors. “The lawyers tend to be better,” he says. “The math in poker is basic arithmetic, it’s not that hard. But you still have people, like a lot of the doctors that I play with, who’d rather not bother with all the math. They feel that they have enough intuition for the game.” Rubin is pleased to point out that they’re frequently wrong. “The fundamental math is much more important. If you’re a solid mathematical player, in the long run you’re going to kill the intuitive player.

Having said that, it's all about psychology.

Yes, poker is all about math and paychology.

And chutzpah.

And sitzfleisch.