Well, compared to other leagues i think the Sinnoh League had very redemptions.
You see, maybe some of you think when the Sinnoh League starts that Ash will only use his current sinnoh team ( Pikachu, Torterra, Infernape, Buizel, Staraptor and Gible ).
But in whole processe, he used, besides that pokemon i wrote, Gliscor, Quilava, Donphan, Noctowl, Sceptile, Torkoal and Heracross, and we dont now who will be the 6th pokemon in the battle with Takuto.
So, in this league, Ash has used at least 13 different pokemon which is pretty good if we remember, for example, the Hoenn League, where used 6 pokemon...
And not only he used a variety of pokemon, but many of his pokemon learn new moves, and we have the return of Gliscor, which all of us think that was impossible, like Primeape, Butterfree or Pidgeot.
And besides that, Cyndaquil evolves into Quilava which was pretty amazing, and other pokemon that Ash didnt use in the league appear, even for some seconds ( Snorlax, Bayleef, Corphish, Bulbasaur, Totodile, Glalie, Muk ).
In other leagues this kind of stuff ( evolutions, new moves, new pokemons ) was not in our minds.
But yet they happen in this league.
In thw whole Sinnoh League, we see, at least, 21 of Ash Pokemon, 21!, i remember again, in the Hoenn League we see 6 of Ash pokemon.
Maybe in Best Wishes we will see even more Ash pokemon, and who knows, not only in the Isshu League.
So im very happy with the redemptions.