Why are there two different names given for the chief ruler of the synagogue in Acts 18 verses 8 and 17?
And Crispus, the chief ruler of the synagogue, believed on the Lord with all his house; and many of the Corinthians hearing believed, and were baptized.
Acts 18:8
Then all the Greeks took Sosthenes, the chief ruler of the synagogue, and beat him before the judgment seat. And Gallio cared for none of those things.
Acts 18:17
This is easily explained if you read the verses in between those two. If it is the same synagogue it is 18 months later; they could have a new chief.
Acts 18:9-11 Then spake the Lord to Paul in the night by a vision, Be not afraid, but speak, and hold not thy peace: 10For I am with thee, and no man shall set on thee to hurt thee: for I have much people in this city. 11And he continued there a year and six months, teaching the word of God among them.