here is my two cents worth:
gamblings winnings may be offset by like gambling losses, meaning if you win 5,000 in football, you may not go to the track and pick up losing tickets and use them to offset that football win. you must show football losses.
of course, gambling is ilegal in itself, other than those sanctioned, or rather, monopolized, by your state, like those immoral lotteries (separate subject?).
the one thing i can tell you about our government, including the irs, is that if and when they come after you for whatever reason, you would wish you could disappear.
from a practical standpoint, though, the government would not be concerned about small time cheating, say something under 100 grand a year, unless you flaunt it (advertise it). keep that in mind, mj writers. i think i have read somewhere that a whopping 75% of taxpayers cheat one way or the other, some very discreetly, and some in excess.
the irs mission is to collect taxes, and that takes time and money, so they will probably not be concerned because someone blew the whistle that you failed to declare 5-10 thousand.
the 10 grand rule applies to cash and semi-cash, like bearer checks or checks endorsed in blank. in other words, any instrument that is negotiable by anybody is like cash, but a check made out to a specific name is not. unsigned travellers checks are like cash.
pep