That's correct.
A running tally is kept of the output rate versus 23.976 (after ignoring soft pulldown). If it exceeds that rate then fields are dropped. If it falls short, fields are added. It's reminiscent of Bresenham's algorithm for line drawing. It was conceived originally by jackei, of course. It's generally useful only for relatively small deviations from pure 3:2 pulldown, e.g., when the main movie is 3:2 but intros and credits are not. That is the reason for the conventional wisdom of when to use force film (90-100% film).
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