Words like elephant and 3-4 hybrid defense have been running rampant all over Raider fan forums and boards.
Fans have been suggesting the Raiders will use an elephant defense, a hybrid defense, or even a straight up 3-4 defense as if they have an inside source and actually know what the Raiders are thinking.
With the majority of Raider practices closed to the media, it is possible that they are showing 4-3 looks at open practices, then switching schemes behind doors. Though not impossible, this is very unlikely.
Reality is all we know is what little we've seen and what Tom Cable has told us. The Raiders have clearly been showing 4-3 looks at practice, and Tom Cable had this to say.
"There are some things that I think will be new for us as a football team. But we're a 4-3 team in terms of our base structure," he said.
As of right now, anything other than a 4-3 defense is pure speculation based on the Raiders bringing in bigger d-linemen and tweener linebackers.