Deuteronomy 18:22
If what a prophet proclaims in the name of the LORD does not take place or come true, that is a message the LORD has not spoken. That prophet has spoken presumptuously. Do not be afraid of him.
Jeremiah 28:9
But the prophet who prophesies peace will be recognized as one truly sent by the LORD only if his prediction comes true."
Ezekiel 33:33
"When all this comes true-and it surely will-then they will know that a prophet has been among them."
Matthew 11:13
For all the Prophets and the Law prophesied until John.
So the Bible says that:
(1) a true prophet must be 100% accurate, and
(2) John the Baptist was the last one