These guys that make the big bucks understand finances better than their counterparts years ago, and they have agents who help them.

Of course the tax structure matters; always has.
A trivial amount can be absorbed as a minor irritation; but a huge tax as in California must be taken into consideration. A football player gets his earnings as earned income, and therefore every dime of it is subject to taxes. A guy who owns a company can set things up differently so that only some is earned income and the rest can be made subject to capital gains or he can do other cute legal tricks to avoid taxes such as being paid in stock options. Players have little choice.

I am a prime example. I moved out of California years ago when it became apparent that the tax structure was going to get worse and worse for middle income and up folks. Glad I did; many good friends and family are now too established and entrenched to pick up and move very easily, but would if they could.

Bottom line; it might not matter much on those first rookie contracts. But on the big bucks deals, you bet it matters. We are talking hundreds of thousands if not millions over a few years. And unless altruism or idealism plays a role, no one wants to throw money into a fire.