" I knew a high stakes poker player who was encumbered with the tax on a 1.2MM take home from online play. Lost it all in the new tax year before he paid for the prior year liability and then wondered why he couldn't offset 1:1. " he has a point. businesses can do it. tell him to check with an accountant.
It's especially hard on pro gamblers since they disallow *any* kind of carry-forwards except for expenses.