A royal flush is a straight flush composed of the highest cards, such as 10? J? Q? K? A?.  But of course they don't all have to be in order. Q? 10? A? J? K? is still a royal flush.  The Royal Flush is the jackpot in video poker, and comes around about once out of every 40,000 or so hands -- or a week and a half of full-time play.  Hey, it could be worse:  The jackpot on a typical slot machine only hits about one out of every 262,144 spins.
Well, the charts on our site are on roughly accurate to within 0.1% of perfect play. So, if you find that game that returns 100.5%, you would be actually earning about 100.4% with our charts - not too bad. Not many charts get much closer than 0.1% because they would have to be extremely long and complicated to explain the subtle differences in rare hands.