Definition
Plain language
How often each single digit of a hidden number is guessed right, rather than the whole number at once.
As stated in the literature
Position-wise recovery rate for a multi-digit secret, with a chance baseline of 10% per position; distinguished from exact-match recovery of the full string.
Also called: per-digit recovery, per digit accuracy
Why it matters: It reveals partial leakage that a whole-secret success rate would hide, and partial leakage can be enough to brute-force the rest.
For example, an attack that correctly names three of a four-digit PIN's positions but never the whole code at once scores well on per-digit accuracy while scoring zero on exact matches.
Heard on the show
“Under the casual one-liner, per-digit recovery on Claude Opus is five point four percent.”Episode 246 — 160 Perfect Refusals, And The Refusals Were The Leak