During the early days of bare-knuckle boxing, a line was scratched across the center of the ring, dividing it into two halves.
This is where the fighters met to start the contest, or where they “toed the line” to begin each round.
If, as the fight progressed, one of the boxers was unable to toe the line without help from his seconds, it was said he had failed to come “up to scratch.”
Somebody that isn’t “up to scratch” is someone that can’t cut it.
