The other reply took a turn so I'll toss my hat in. I do not tip solely based on performance. I know that sometimes people have a shit day. Maybe they have extra tables.

This is the wrong reason for tips to exist. You don't tip service staff to make their wage, it is incredibly rare, so rare in fact that I have never even heard of a place where the staff rely on tips just to make minimum wage because they are being paid below minimum wage. It's a myth perpetuated by disgruntled people who have no skills and want an excuse to treat other people like shit because their life is terrible because of the terrible life decisions they continue to make.

Find me a restaurant that pays their staff below minimum wage and relies on tips to meet that minimum wage, and I'll show you a business that will be shut down by the labor board.

You do not deserve a tip to make your wage, the tip is the for PERFORMANCE. That's why it's called a tip, or a gratuity and not an allowance or compensation.