Earlier inI posited a wild, speculative theory that Oklahoma's defense has two different masters with two very different approaches to gameplanning.One is Big Game Bob, an aggressive tactician that loves to go for the throat, throw punches, and see what happens. The other is cautious Mike, who's scared to death of anything that would set his secondary up for trouble or result in a bad beat.I don't think the theory is totally insane, although much of it is speculative, so I'm going to lay out my reasons for believing there is at least some validity to the idea of a splintered philosophy in Norman.First let's go back to 2012. The Sooners had just been beat by Tech at home and Ok St and Baylor on the road in a disappointing season that resulted in the unthinkable, a Cowboy Big 12 championship. The play of the secondary had been a central point of contention and after deposing the secondary coach (Willie Martinez, now at Tennessee) Bob got a chance to bring back his brother Mike who'd just been fired from Arizona after several lackluster seasons.The only problem was that Brent Venables, the linebacker coach, had gotten used to being the sole defensive coordinator (aside from the oversight of Big Game Bob himself, of course) and had been doing an excellent job of it. I've never heard anything that would confirm this to be true but it's hard not to believe that having to share the job with Mike again led Venables to cut out on his own and head to Clemson.There he's continued to craft aggressive, versatile defenses that virtually always rank in the top 10 in S&P at the end of the year . But I'm not looking to pour salt in that wound, let's move on to what happened under Mike's direction at Oklahoma.The Sooners made two major changes in year one under "cautious" Mike. First, they converted the DL technique up front to a two-gapping, read and react style of play comparable to what Pellini was teaching at Nebraska. Secondly, they began playing dime personnel against four-wide formations so that they could play tight cover four or pure man-free coverage. That left them with five in the box more often than not unless they dropped down Tony Jefferson or Javon Harris into the box, which they did at times.The result was the nation's 2nd best passing defense by S&P but a porous run defense . In 2013 they adjusted to play more two-linebacker sets and with Aaron Colvin and nickel/dime defenders Gabe Wilson and Julian Wilson returning they were able to play a 4-2-5 nickel set that could play cover 1 and protect the linebackers more. It was this year that they discovered they had a blitzing fiend in Eric Striker but he was often playing on the edge against big-bodied opponents.In 2014 they converted to the 3-4 defense, which meant playing three "read and react," defensive tackle-sized D-linemen and then mixing in big blitzes and plenty more man coverage. They also moved Eric Striker out to the "nickel" or space-backer position.This year featured my favorite cautious Mike gameplan, against the Baylor Bears. Bryce Petty and the Bears had recently lost a game against West Virginia in which Tony Gibson had utilized what I call the "all or nothing" approach to stopping the veer and shoot.The idea is to embrace the extremes of the veer and shoot scheme by matching it with extreme responses. The Mountaineers were either bringing zero blitzes or playing max coverage and bracketing all of the Bears' option routes. This totally befuddled Bryce Petty and their offense and led to a big West Virginia upset. The following week, the Bears beat Kansas 60-14, because Kansas, and then Bryce Petty had the following presser:That's the kind of bravado you normally associate with Oklahoma. As it turned out, Petty and the Bears were ready for OU.Mike Stoops tried to match the "all or nothing" gameplan to stop Petty but did so with off coverage on his zero blitzes rather than press-man as Tony Gibson had done. That led to an interesting result...The previous drive to this one the Bears had busted out their empty formation and found the Sooners bringing the "all or nothing" tactics they'd seen against West Virginia but with off coverage. The Bears punished it with a TD drive, but then uncorked this wonderful drive coming out of halftime:What you sadly miss in that drive is in exchange in which right cornerback Julian Wilson, whom you see picked on here mercilessly, went over to the sideline to yell at Mike Stoops in the middle of the game.This all led to the hire of DB coach Kerry Cooks and the banishment of frustrated, cautious Mike up to the press box.The following year the Sooners had a much better gameplan for the Bears, albeit one that benefitted from facing a freshman quarterback, and they won the conference despite getting whipped again by Texas in the Red River Shootout. They did it in an unorthodox fashion, keeping extra linebackers on the field but then using them to protect the secondary and allow them to bracket Baylor's biggest threats . Normally you use 3-4 OLBs to protect your secondary via the blitz but hey, it worked!The second Mike Stoops era in Okahoma has been characterized by block-catching, read and react, conservative play up front that is totally contrary to how the team played when Venables had more input on the philosophy. They're still aggressive on the back end, mixing in lots of man coverage, man blitzes, and trying to teach their DBs to attack routes and tendencies, but Mike Stoops protects his secondary every chance he gets.He's trying to win games with his defensive backs, who in a given year may or may not be up for it, and he tends to protect them whenever he can. Just the other week he was bringing only two or three pass-rushers against Greg Ward in a fruitless effort to shield his secondary from harm I think Mike Stoops, or second era Mike Stoops at least, lacks the confidence to play with the kind of aggression that once characterized Stoops/Venables defenses. His imprint on the Sooner philosophy has been one of restraint and caution, which I think clashes with Big Game Bob's own preferences and occasionally results in some overly conservative game plans.Perhaps the problem is that they just don't teach and develop cornerbacks well enough for Mike to justify a more aggressive approach. Perhaps there's no difference between what Big Game Bob wants and what cautious Mike thinks is best but there are real schematic differences between Brent Venables and Mike Stoops. Either Venables was responsible for the aggression or Big Game Bob has a soft spot for his little brother. Given how Bob likes his offense to play (aggressively) I'm guessing it's the latter.But it used to be that Oklahoma defensive failures would look like the king leading a sortie to drive the defenders away from the castle and going down fighting in front of the walls. Now it looks like opponents tearing down the walls and dragging the king screaming out of his keep.Which response will we see on Saturday night? Will Big Game Bob come roaring out of the gates on horseback?Or will cautious Mike be directing the defense from the highest tower?