User blog comment:SayuriDarling/The Mark of Athena Official Discussion/@comment-4517591-20121006071543/@comment-3146930-20121006192657

While Percy may be one of the best swordsman in the last 300 years, the guy he was fighting has been around for thousands of years, being the first to ever use an Imperial Gold blade. Also, someone gets better at swordplay when they fight stronger appoinents, but if Percy has no one to practise against (I mean how often does he fight a sword master?) then he can't improve and will become rusty, like at the end of The Sea of Monsters when he fought Luke.