A: Long-running series with each episode covering a lot of canon material e.g. two to four chapters.
The pacing is great, and viewers can enjoy watching an episode that is practically filler-free. However, since there is a lot of canon material being animated into one episode, the gap between the anime and the manga is usually small. As a result, there needs to be filler arcs to prevent the anime from reaching the manga. Examples of series that follow(ed) this structure are Naruto, Bleach and early One Piece, where the pacing is excellent but there are a lot of filler arcs.
B: Long-running series with each episode covering less canon material e.g. no more than one chapter.
Here, the pacing is much slower because each episode covers lesser canon material. Thus, an episode created from this structure would usually contain a lot of filler scenes. Though, these fillers are generally more related to the canon material, as the small amount of canon material is dragged out into one, long episode. Additionally, there are lesser and/or shorter filler arcs, as the fillers are integrated within the canon material and there is usually no concern for the anime to reach the manga due to the slow pacing. One Piece is one series that currently has this structure, where the pacing is slow but there are lesser/shorter filler arcs.
C: Short-running series with each episode covering a lot of canon material.
Series that have this structure (such as Attack on Titan) generally have beautiful art and animation, on a very consistent scale. There are no filler episodes at all and each episode is entirely canon. It has all of the advantages of structures A and B. The only downside is that it takes a lot of time to create these high-quality episodes. Thus, there are usually long breaks between seasons and you may have to wait for two years just to watch the next episode.
Note: By long-running series, I meant series that have an episode released every week (except on special occasions such as Japanese holidays when there are breaks). Short-running series don't have this week-to-week schedule. They may release an episode each week, but they only do it for a specific period of time before having a long break.
Also note that there are variations to these structures. For example, Naruto episodes sometimes cover less than one chapter. So consider this thread in general terms.
The pacing is great, and viewers can enjoy watching an episode that is practically filler-free. However, since there is a lot of canon material being animated into one episode, the gap between the anime and the manga is usually small. As a result, there needs to be filler arcs to prevent the anime from reaching the manga. Examples of series that follow(ed) this structure are Naruto, Bleach and early One Piece, where the pacing is excellent but there are a lot of filler arcs.
B: Long-running series with each episode covering less canon material e.g. no more than one chapter.
Here, the pacing is much slower because each episode covers lesser canon material. Thus, an episode created from this structure would usually contain a lot of filler scenes. Though, these fillers are generally more related to the canon material, as the small amount of canon material is dragged out into one, long episode. Additionally, there are lesser and/or shorter filler arcs, as the fillers are integrated within the canon material and there is usually no concern for the anime to reach the manga due to the slow pacing. One Piece is one series that currently has this structure, where the pacing is slow but there are lesser/shorter filler arcs.
C: Short-running series with each episode covering a lot of canon material.
Series that have this structure (such as Attack on Titan) generally have beautiful art and animation, on a very consistent scale. There are no filler episodes at all and each episode is entirely canon. It has all of the advantages of structures A and B. The only downside is that it takes a lot of time to create these high-quality episodes. Thus, there are usually long breaks between seasons and you may have to wait for two years just to watch the next episode.
Note: By long-running series, I meant series that have an episode released every week (except on special occasions such as Japanese holidays when there are breaks). Short-running series don't have this week-to-week schedule. They may release an episode each week, but they only do it for a specific period of time before having a long break.
Also note that there are variations to these structures. For example, Naruto episodes sometimes cover less than one chapter. So consider this thread in general terms.