[BottlesOf]

Diligent ones.

I'm assuming you live in the US, and I'm assuming you aren't filing a schedule C as a professional poker player.

Therefore, the Fed requires you to provide your total gambling winnings and total gambling losses you cannot just provide your net, and you cannot deduct in excess of your winnings.

To calculate total wins or total losses you need to sum all of your winning sessions and all your losing sessions. The IRS doesn't do a great job of defining an online "session" but some gambling tax experts have said that a continuous period of play at the same limit is a session, even if at multiple tables. However, different limits/games, different session. Use the search function or pm me later and I can send a link to the source.

You shold be able to back up what you claim by having a record of all your sessions. Where played, how much won/lost, etc.