As a pro over thousands of hands? Less than 5%... A amateur over thousands of hands and not actively implementing strategy to become better... Luck could potentially be as high as fifty plus percent. See this is a tough question to answer. You give a pro luck and a weekend warrior the same luck a pro will optimally play that lucky hand the correct way and optimize the winnings. Luck has very little to do with the game at a high level. It's the know how to optimally play your positions, scenarios etc... That puts the pro's on a whole other level than a lucky fish.