Why most of a show runs on twos

It’s a common assumption that animating “on ones” — a new drawing every frame, 24 a second — is simply the higher-quality option, and everything else is a compromise. That’s not quite right. Twelve unique drawings a second, each held for two frames, still reads as smooth motion to almost any viewer under normal circumstances; the difference is legible mostly in fast, large-scale movement, which is exactly why studios spend their ones budget on fight climaxes and transformation sequences rather than on dialogue scenes where nothing but a mouth and an eyebrow are moving.

A 24-minute TV episode animated entirely on ones would need roughly double the drawings of the same episode on twos — for a genga+douga count that’s often already in the thousands, that’s not a stylistic choice most schedules can absorb.