O'Brien worked under Belichick in New England and uses many aspects of that system today, but the similarities may end there. Quarterbacks coach George Godsey was an assistant in Belichick's offense, brought over by O'Brien in 2011.
"I mean, I think we're all different," Godsey said in his Thursday press conference. "At some point I think we have a relationship because we worked together, but certainly we're not at all the same or we don't have the same interests, too. I think when you coach for certain coaches that are successful, whether at college ranks or at the pro ranks, you often get compared to them. But we're all our own individual coaching (style). My coaching style is a little bit different than Billy's (O'Brien) and Billy's is different than mine, and so forth."
NFL Network analyst and former Patriot linebacker Willie McGinest had a chance to visit the Texans at OTAs this week. McGinest won three Super Bowl rings under Belichick but even in his limited time with O'Brien, he noted that the two were very different.
"Bill O'Brien has his own coaching style," McGinest said on Texans Radio Thursday. "You would be crazy not to take from other coaches. You take little things here and there and you apply it to what you are trying to do and try to implement it. It's not like you're trying to be like that person but there's nothing wrong with taking information or certain things from somebody who's been really, really successful. Billy (O'Brien) has that attitude. He's demanding. He has all the right tools: he's smart, he knows how to communicate, relate to the players, he's changing the culture here. Of course when you've coached with some of the best, you take a little from everybody."
O'Brien considers the Belichick, the longest-tenured active coach in the NFL, a friend and a mentor. He gave him his first start in coaching in the NFL and played a big part in his career.
"He played a big role," O'Brien said on March 25. "He hired me to be a coaching assistant in 2007. I'm the first coach in the history of football to go from 0-12 at Duke University to being 18-0 before we lost the last game, 18-1. He gave me that opportunity and then promoted me up through the ranks there. I owe him a great deal. I learned a lot from him. I think that's well-documented. I've said that a number of times. He's been a great friend and mentor to me in this profession."