Winston could be the No. 1 pick, assuming he avoids any further off-field slip-ups between now and late April. He also could slide deeper down Round 1 or even into Round 2 if enough QB-needy teams decide he's not worth the trouble. For as talented as he and Mariota are, there are limited first-round landing spots at quarterback: Tampa Bay, Tennessee, the Jets, Chicago (if it sheds Jay Cutler), St. Louis, Houston and maybe Philadelphia round out the likely possibilities.
Why the Rams? Well, let's start with the draft position at No. 10. This would be a glorious opportunity for them, one year after bulking up along the offensive and defensive lines. They also do not have any tangible answer at quarterback, in spite of their continued backing of Sam Bradford. Sticking with Bradford does not preclude the Rams bringing in a QB to compete for the job now or in 2016.
Winston is a so-called general on the field -- a confident leader capable of taking charge when his team has the ball. He's confident in pre-snap reads, has a strong enough arm to make every throw and offers a valuable size/speed combo.