What this is
How long a Pokémon card stays legal in Japan's main competitive format: about three years, with one in three card groups rotating out each January since 2021.
How it’s built
- Cards carry a letter mark. Official rotation notices give when each mark joins and leaves the Standard format.
- Marks E, F and G each lasted 3.0 to 3.1 years; rotations have come every 357 to 371 days since 2021.
What we assumed
- A mark's legal life starts on the date of its first product.That is when the notices say the mark joins Standard, so it is the natural start date.
Sanity check
The English rules state the same policy: the oldest mark leaves when a new one arrives. Before 2021 the gap between rotations was longer (420–454 days).
Where it comes from
Our calculation from other figures in the trainer’s notes:
Show the working
- Median interval 2021-2026 days: 364
- Legal marks at any time: 3
- Share of marks leaving each rotation: 1 of 3
- E 2020-12-04..2024-01-26 = 1,148 d (3.14 y)
- F 2021-12-17..2025-01-24 = 1,134 d (3.10 y)
- G 2023-01-20..2026-01-23 = 1,099 d (3.01 y)
- intervals 454, 420, 357, 371, 371, 364, 364 d