Well, I think Ash has matured big time. Remember in Kanto he really didn't know what he was doing, at all? He didn't even win half of his badges by battling. He was also kind of mentored by Brock and Misty. In the Orange Island, he got a bit better. In Johto, his skills had improved. But yes he has matured. It all really happened at the end of Johto, his battle wit Gary was kind of epic, Then in Hoenn, he became the teacher(to May) instead of the student. I really enjoyed his process in Hoenn. In the Battle Frontier, a few matches was great, like the first one, second and last. In Sinnoh, It was like he was learning all over again, I have to say, I really didn't expect him to take out two legendary Pokemon, and now in Isshu, It's like he's starting all over again, which I don't mind, because if Ash was great at everything, wouldn't that be boring?