When the Redskins drafted Keenan Robinson in the fourth round last month, they were doing what worked for them just two years ago.In the 2010 draft, they tabbed LSU outside linebacker Perry Riley in the fourth round. He played on the outside for the Tigers but the Redskins had him pegged to succeed Rocky McIntosh, a pending free agent, on the inside next to London Fletcher. After playing just a handful of snaps on defense as a rookie, Riley took over the starting job from McIntosh midway through last season and, while he is still learning, he appears to be set for a long run at the position.After signing the 37-year-old Fletcher to a two-year deal, one that presumably will be the last contract of his career, the Redskins got down to business with succession planning at his position. They saw the athletic ability and versatility they are looking for at the position in Robinson, who played both inside and outside linebacker at Texas.I try to play tough between the tackles. Im good in pass coverage, thats another element I bring to my game, and I feel like I can play sideline to sideline, said Robinson after the Redskins rookie minicamp concluded on Sunday.Although he believes he has some game, he realizes that being in the NFL is a different game altogether. I feel like Im a freshman starting out again and Ill just have to work my way all the way back up, he said.If he didnt realize that before, he did when the Redskins gave him their sizeable defensive playbook. Yes, it was about a triple cheeseburger worth, Robinson said with a smile.Robinsons approach to learning the playbook was similar to how he might eat that triple cheeseburgerone bite at a time.Once you get the concepts down with the defense you can pick it up real quickly, he said. Once you just get the concepts and the terminology everything else kind of flows from there.Robinson was teammates with current Redskins linebacker Brian Orakpo at Texas and he said that he has watched a lot of Redskins games because of that. He plans on learning a lot from Orakpo and from the man he could replace in 2014.Im going to be right there, trying to learn everything I can from the Fletcher especially since hes one of those guys who have done it for so long and able to play injury free, said Robinson. So Im going to learn everything I can from him and use his advice to my advantage.