Hopefully all of them. After all, this is what happened to John the Baptist and Saul/Paul. I could make a case that this also happened to Mary, mother of Jesus.
These conversions would be inconsistent with most of the arguments for free will that I have read on this board. They would be consistent with the Monergist position. I don't want to put words in your mouth, but perhaps what you are hinting at is that God makes exceptions even though the biblical model (according to free will proponents) is free will before regeneration? If so, then we can't stop at "exceptions" like JTB, Paul, or Mary; we have to extend it to Joseph, Moses, Abraham, Isaac, Jacob, David, Solomon, Isaiah, Jeremiah et. al. And since God shows no partiality (Romans 2:11-16), how can we limit His exceptions just to noted biblical figures? Regeneration before belief/faith should apply to all. Regeneration before belief/faith is the Monergist position.
It just so happens that I sat under a lecture by the late Dr. Charles Ryrie a number of years back. He was asked a question along the lines of, "If the Calvinist view of predestination and election is wrong, how do we reconcile God using some of the most famous people in the Bible? It doesn't look like all of them had a choice." Dr. Ryrie's answer was very interesting and refreshingly honest. He said that there were only three possible answers to the question. 1. A free will choice, while not clearly explained, is implied because the theological position [free will] demands consistency. 2. The Calvinist view is correct. 3. It is a mystery, but one on shaky ground, because there is no warrant in Scripture. Dr. Ryrie said that #1 was the only choice he could make and be honest with his doctrinal convictions. What was honest about Dr. Ryrie's answer was that he remained consistent with his theological convictions. He recognized the difficulty presented by all three answers but chose the one he believed in most. If he chose #2 then...well...I think we know how that would have gone
Correction. According to your description of the free will position.
Isn't that a given for any opinion expressed on this board? And while it is my opinion, how is it free will if God violates it? I was a Synergist for neigh on 20 years. I never heard one gospel message from a free will preacher that did not emphasize the choice of the individual as being the determining factor as to their coming to faith in Christ. The late evangelist Jack Wrytzen was famous for the following appeal that he gave at every invitation, "If you can't stand up for God here, surrounded by all these people, you'll never be able to stand for him anywhere!" Jerry Falwell used to preach similarly. I am not saying there are free will preachers that don't misspeak or make exceptions, but it is not the norm.
Those are free will hallmarks, not Monergist ones. To be consistent free will believers need to remember this.
Anybody that believes this is confused, never mind free willer or not.
I totally agree.