Billick, who had Pettine as his assistant at the Ravens, said that the Browns have appointed a strong-willed and determined coach who was the best of all the options available to appoint.
"Regardless of how long it took or whoever else they interviewed, they got a good man," he told ESPN. "That's the bottom line. I'm sure once they sat down with Mike, they saw the strength of personality. He's got a great football mind. He is very organised.
"Make no mistake, you have a very firm, strong-willed head coach right now, and he will make sure, in no uncertain terms, that the players understand that, the coaches understand that and the organisation understands that. I mean that in a positive way. There's no ambiguity as to what Mike wants and how he wants it done."
The Browns finished the 2013 season with a 4-12 record.