Recent tax changes (effective with Tax Year 2018) are going to cost some of those who file as a "Professional Gambler" significantly more money than in the previous years.
https://www.journalofaccountancy.com...et-losses.html
Reversing a precedent that was established about 10 years ago, the Tax language was revised so that wagering and the associated expenses to do so are again lumped together.
Under the precedent, one could have a losing year wager-wise, but still benefit financially by deducting expenses. Starting with tax year 2018, "business-related" expenses can now only be deducted against and up to the amount of one's winnings, thus eliminating the situation known as a Net Operating Loss.
This will be particularly difficult for those who are not consistently and significantly profitable year after year.
Those who engage in wagering as a hobbyist (not filing under a schedule "C") will be unaffected by the new tax change.