Right now I am only listing the downside to being a professional gambler. I may add more later.
Although professional gamblers have the reputation of constantly riding highs and lows, one of the risks of being a professional gambler, ironically, is pathological boredom. The way that someone becomes a successful gambler is that they discover a mathematically valid strategy and repeat that strategy as much as possible. Whether it is playing limit poker or blackjack, this can become extremely boring over the course of years. This may seem like a relatively benign affliction (and, admittedly, it is compared to the other risks), it is still a large enough risk factor that motivates most professional gamblers to quit gambling for a living after about 3-5 years. Most successful gamblers, after making 6-figures for many years in a row, always seem to get to a point where they are "moving on" to something "bigger and better".
The other side to gambling taxes is that many profitable gamblers may not pay taxes on their winnings if their winnings are small. Although these small winnings are taxable, and should be reported, they frequently are not reported if the gambler knows that the winnings are not traceable (due to the IRS not being notified of the winnings). Eventually though, a profitable gambler who transitions into being a professional gambler will realize that their larger and larger winnings will be documented in bank accounts - so they start paying taxes. But, many times, they may have already spent the money they owe on past winnings - or, at the very least, are disappointed that some of their winnings are being "taken away" (for lack of a better phrase).
HPG ADMIN on January 1, 2014