Gambling winnings are a taxable source of income. Football, basketball, baseball, horse races, blackjack, etc., all of these qualify. If you make a profit, the IRS says you must report it.
Good news is, gambling losses can be used to offset your winnings. So if you make $20,000 gambling but you also lose $20,000, your total taxable income would be $0. Which means you would owe no tax on your winnings!
There is a limit though. If gambling losses exceed profits the excess losses are not deductible. So if you make $20,000 gambling but you lose $30,000, the excess $10k is not deductible.
Lastly, losses are only deductible if you itemize.
If you have questions, let us know, we're always happy to help.