The new tax law starting in 2018 has a tax deduction called 199A. There is some discussion about this over at BJ21 on green chip. I'm not convinced this deduction applies to a professional gambler. My reasoning is this:

Qualified trades and businesses include all trades and businesses except the trade or business of performing services as an employee and "specified service" trades or businesses: those involving the performance of services in law, accounting, financial services, and several other enumerated fields, or where the business's principal asset is the reputation or skill of one or more owners or employees.

Wouldn't a professional gambler come under "the business's principal asset is the reputation or skill of one or more owners or employees."

Anyway Captain Jack says is applies to professional gamblers if you file as a business and I'm looking for some proof. A passage or something that spells this out. Captain Jack provided this link and I'm overwhelmed by it.
https://www.irs.gov/pub/irs-drop/reg-107892-18.pdf

Here are some other sources of info.
https://www.thetaxadviser.com/issues...deduction.html

https://www.bdo.com/insights/tax/fed...199a-deduction

Anyway, I was hoping a tax lawyer, CPA or anyone else with more insight could weigh in and explain this monster.