Quick answer
One word lands on a person who can hear. A hundred blows accomplish nothing on a person who cannot, and the ratio is the verse's whole argument.
Read both lines
The comparison is about efficiency, and it is deliberately lopsided: one against a hundred, a word against physical force. What the verse establishes is that correction works by reception rather than by pressure, so escalating force on someone who will not receive it is simply wasted. That is a practical observation for anyone who has tried to fix a person by increasing the volume. The book has been saying it since 9:8 and will say it again, and here it puts a number on the futility.
Related: Proverbs 9:8 · Proverbs 27:22 · Proverbs 13:1
New King James Version®, Copyright © 1982, Thomas Nelson. All rights reserved. Full copyright information. Scripture provided by API.Bible.
Go Deeper
If this verse has been used to put weight on you that it was never carrying, ask about it directly.