With the exception of cash transactions of $10k or more which require a CTR to be filed, nobody records how much poker players buy in or cash out. It just isn’t feasible; people come to the table with chips, people buy chips at the cage, people buy chips at the table from the dealer, people buy chips from other players at the table, people put cash in the pot (in Nevada they do, I don’t know about other states), people go home with their chips because they know they are coming back tomorrow … no possible way for anybody to even attempt to track how an individual did in live poker.
Yes, I’m quite aware that winnings are reported in tournaments of a certain size. The OP did not seem to be talking about winning a million dollars in a major poker tournament, he asked about getting drunk and lucky. Tournaments with that kind of prize pool take several days to play; they’re not spur of the moment binge affairs and no drunk tourist has ever come close to winning one.
I don’t feel 25 years working in the casino industry and an additional 20 years as a professional gambler amount to anecdotes; I suggest that my experience will provide better answers than 60 seconds on Google. I have filed thousands of CTRs on players as part of my job and I have filed tax returns as a professional gambler for well over 20 years, since a significant portion of my income came from playing even during the years I had a job.
We have mentioned the specific cases of slot machines, Keno, and poker tournaments; notice that these all have a specific buy in and a specific pay out. Such is not the case with live table games or card games in which money and chips come into play from various sources and change hands very quickly, making it impossible to track with the kind of accuracy that would be required to file a legally binding document stating a certain amount of win or loss.
With the aforementioned exceptions, casinos do not report your winnings to any government agency … it just isn’t possible. The main documentation that professional gamblers provide to the IRS is a personal daily diary of their results, although some, such as professional slot players, will also have stacks of papers from slot jackpots.
How a drunken tourist who happens to beat the table games and who manages to actually make it home with a large of money handles his tax situation is between him and the IRS. The casinos simply do not get involved. I’ll mention also that it is such a rare occurrence, the IRS isn’t very concerned with it either.
These are anecdotes: In all my years in casinos, I saw one guy buy in on a Blackjack game for $100 and start betting $5/hand. He started winning and gradually increasing his bets. He won $10,000 and left the casino but I don’t know if he actually made it home with the money. I saw a local woman, a regular player who routinely started betting $25/hand and usually lost a thousand or two get drunk and pull ahead $60,000; she went home broke. And I saw an unknown drunk pull ahead $267,000 on Craps; he also went home broke. While big players regularly win or lose thousands or even hundreds of thousands of dollars, those three are the only times I have seen a low level player hit a streak that got to $10k or more. Sorry if this crushes anybody’s dream, but except on very rare occasions, to win big you gotta bet big.
Hope this has cleared up any confusion.