[Kurn, son of Mogh]

First of all, you can't just claim your net. That's expressly forbidden in IRS Pub 529 (how many times have I written this?)

You have to claim winning sessions as income and losing sessions as itemized deductions.

There is also a school of thought that suggests you can claim deposits as losses and cashouts as wins, but that gets disputed and I've heard several cogent arguments on both sides.

Best idea is to hire a good accountant who is familiar with these things.