AK in position vs an unexpected river bet

[Shillx]

I would play it this way against every opponent. If the board were something like AQxxx or AJxxx then you have to be more careful. The only hands that need to worry about here are AA and 99. He doesn't have AA and 99 just got 1/3 as likely (though doubtful he would play it this way to begin with). You are probably looking at AQ here from the villian.

Brad