AVERAGE ARC LENGHT AND PERCENTILES
First, it’s important to point out that most of the following analysis has been made based on the fact that arcs have an official beginning and an official ending (more or less), while Saga’s grouping is always on the readers so it’s far from being something that come directly from Oda.
I put all my calculations in the following Google Sheet, using datas from the previous bar chart and open data from the wiki. For all different arcs I put down their duration (in chapters and in days) and the beginning time, that is the elapsed time (measured in days) since the beginning of that specific arc since the beginning of the series.
Arcs have been further divided into their length percentiles to make more meaningful description about their likely length.
| Percentile | Ordinal Rank | Ordinal Ranked Arc | Average Length | Standard Deviation | Variation |
|---|---|---|---|---|---|
| 25th | 8 | Amazon Lily | 7.37 | 2.61 | 0.35 |
| 50th | 16 | Sabaody | 18.9 | 3.52 | 0.19 |
| 75th | 24 | Fish-Man Island | 38 | 11.28 | 0.30 |
| 100th | 31 | Dressrosa | 77.5 | 16.5 | 0.21 |
- Minimum Arcs: Logue Town, Reverse Mountain, Return to Sabaody, Reverie, Romance Dawn, Whiskey Peak, Post-Enies Lobby, Amazon Lily;
- Minimum arcs are the arcs below the 25th percentile (or the 25% shorter arcs), all with 11 chapters or less. They are often transitional arcs and their length has been kept constant during the series. The sample is polydisperse for Minimum arcs.
- Short Arcs: Orange Town, Little Garden, Post-War, Jaya, Long Ring Long Land, Syrup Village, Zou, Sabaody;
- Short arcs are the arcs in between the 25th percentile and the 50th percentile (or the 50% shorter arcs), all within an interval given by 11 to 25 chapters. Their content is usually self-conclusive and act rarely as very small transitional arcs, but they are never the payoff arc within a saga.
- Medium Arcs: Drum Island, Impel Down, Baratie, Arlong Parc, Marineford, Punk Hazard, Thriller Bark, Fish-Man Island;
- Medium arcs are the arcs in between the 50th percentile and the 75th percentile (or the 75% shorter arcs), all within an interval given by 25 to 50 chapters. Their content is always self-conclusive, with Big Boss Battle for Luffy and, sometimes, for some of the other crew members. Arguably, as seen in the statistical analysis, this could have been split up in between short arcs and long arcs (putting 30-ish chapters as an arbitrary separation), but I prefer to kept the slip to the a priori chosen percentiles.
- Long Arcs: Water 7, Enies Lobby, Alabasta, Skypiea, Wano*, Whole Cake, Dressrosa;
- Long arcs are the arcs above the 75th percentile (or the 25% longer arcs), all with more than 50 chapters. They are long arcs (except Water 7) that have a long conflict between the Strawhats and an enemy crew, with a main fight with the Big Boss and Luffy and most of the other Strawhats with a main enemy. Long arcs are payoff to long sagas.
This sub-classification is useful to look at different arcs from a descriptive point of view.
Since we have 175-ish chapters left, shouldn’t we just take the averages length and determine how many of those arcs we have left? Sadly, it’s not that easy. The main problem to determine how many arcs we have left is that, as the series went on, arc’s length has kept growing longer and longer.
