SANTA CLARA, Calif. - Colin Kaepernick is a wanted man. NFL coaches are going back to school to figure out ways to stop fleet-footed quarterbacks like him. They're peppering pro prospects with questions about how to thwart the spread offenses that vexed them in 2012. And they're planning to draft speedy tacklers and edge defenders who can keep pace. Naturally, Kaepernick wants to stay a step - perhaps even two - ahead of the defenses.