Some of the reasons for Louisville quarterback Lamar Jackson's explosion onto the national scene are obvious.His strong arm. His blazing speed. His rare athleticism.But the biggest one might be the hardest to see when his No. 10 Cardinals host No. 2 Florida State on Saturday in the first top-10 matchup of the season and the biggest game in the history of Louisville football. Jackson actually knows what he's supposed to do. "I really didn't know any of the plays last year," Jackson said. Jackson wasn't being humble or trying to deflect praise at the ACC's football kickoff in July; he literally didn't know the plays. "You didn't really have to watch film to notice it," coach Bobby Petrino said. "There would be times when you'd say, 'He really had no idea on that play, did he?' "Jackson had no idea because he had never had an actual playbook to study before. When he starred at Boynton Beach High, his coaches didn't give out paper or digital diagrams of their plays; they stressed onfield reps and film study instead. The team didn't have a lot of plays, either, and the ones they called relied on easy reads that wouldn't slow Jackson down by causing him to think too much."We tried to keep things as simple as possible so he could just be an athlete," said Daniel Start, Boynton Beach's offensive coordinator during Jackson's junior season. "We weren't asking him to do a lot — just make simple reads and throws. At that point, you just turn a kid like that loose and try not to overcoach him." The plan worked. Jackson finished his senior season with 39 touchdowns (20 passing, 19 rushing) as Palm Beach County's player of the year. When Jackson arrived at Louisville last year, the Cardinals made some adjustments to get their four-star recruit on the field as a true freshman. They used the shotgun formation more often because that's what he did in high school. They only called plays they thought Jackson understood.But Jackson was still lost. He would stare down one receiver. If that teammate was open, Jackson would throw to him. If not, he would run. "He's just so fast and elusive," dinals linebacker Keith Kelsey said, "half the time, you wouldn't know if he messed up or not."Even with the mess-ups, Jackson's first season was a success. The 6-foot-3, 205-pound athlete put up 307 passing yards and three touchdowns at Florida State. He finished second in the ACC's offensive rookie of the year voting and helped the Cardinals to a 7-5 regular season before Louisville used its bowl practices to reinstall the offense. "I didn't know anything," Jackson said. "I sat down by myself and hit the books hard." By the time the Music City Bowl rolled around, Jackson was ready to star. He torched Texas A&M for two rushing touchdowns and two passing ones, becoming the third quarterback ever to rush and pass for 200 yards in the same bowl game. Jackson continued to cram in the offseason with film sessions in the morning and throwing sessions in the afternoon. The progress has been obvious through his first two games. He's the top player for a team that's playing like a contender for the Jan. 9 national title game at Raymond James Stadium. He's the nation's third-leading rusher and eighth-leading passer, and his 13 touchdowns (six rushing, seven passing) are the most in the country. His 37 completions have gone to 10 different receivers — a sign he understands the system well enough to exploit the biggest defensive hole each play."We've played against him, so we know what he's like," FSU coach Jimbo Fisher said. "But that doesn't make it any easier." Especially now that Jackson actually knows what he's supposed to do. Contact Matt Baker at email@example.com. Follow @MBakerTBTimes.