I thought it would be appropriate to start a separate thread about professional players and their tax deductions, since we have some pros here and APs who want to maximize their returns both in casinos and with the IRS.

Here are a couple of bits of info from the IRS that might be useful and might start off the conversation:

To be deductible for tax purposes, expenses incurred for travel, meals, and entertainment must be ordinary and necessary expenses incurred while carrying on your trade or business. Generally, you also must show that entertainment expenses (including meals) are directly related to, or associated with, the conduct of your trade or business.

For 2014, the standard mileage rate for the cost of operating your car for business use is 56 cents per mile.

lodging and meals: your lodging and meals if your business trip is overnight or long
enough that you need to stop for sleep or rest to properly perform your
duties. Meals include amounts spent for food, beverages, taxes, and
related tips.

You cannot deduct expenses for meals that are lavish or extravagant. An expense is not considered lavish or extravagant if it is reasonable based on the facts and circumstances. Expenses will not be disallowed merely because they are more than
a fixed dollar amount or take place at deluxe restaurants, hotels, nightclubs, or resorts.

50% limit on meals. You can figure your meals expense using either of the following
methods.
Actual cost.
The standard meal allowance.

But, regardless of the method you use, you generally can deduct only 50% of the unreimbursed cost of your meals.