Splinter group

From the same book.
??
(it is said about someone that is angry or down)

Judy
Israel

THE PRINCE AND BETTY PG Wodehouse 1912
Gee, we'll wipe Monte Carlo clean off the map. We'll have 'em licked to a splinter. We--It's the greatest scheme on earth."
I've never heard this phrase before! It seems to mean "We'll beat them easily."

Some further thoughts! Licked has two meanings; one is to beat in a fight. A splinter is just a fragment of something wooden, a weapon perhaps. Perhaps the phrase was common in Wodehouse's circle of friends, or perhaps he invented it himself. It doesn't seem to have widespread usage.