Sorry guys, I got sidetracked.
It's my opinion that
the offensive line is the most difficult position to play as a true freshman, specifically the tackle position, but followed closely by the interior line.
First off, as many of you guys noted, most freshman aren't physically developed nor strong enough to come in and match up with defensive lineman who have spent the past several years in a college strength program, and who may be as many as four years their elder.
I believe talent can overcome youth more easily at skill positions such as running back, wide receiver, and tailback. These positions don't require the same level of strength/technique, thus allowing pure athleticism to sometimes takeover.
One such metric I like to consider when addressing this topic is the Wonderlic, which is used by the NFL. While certainly not an end-all test, I think the results when grouped by position are very telling.
Consider the reported average scores by position: Offensive tackle 26, Center 25, Quarterback 24, Guard 23, Tight end 22, Safety 19, Linebacker 19, Cornerback 18, Wide receiver 17, Fullback 17, Halfback 15.
Here is the same data in chart form:
As you can see, the offensive line and tight end position make up four of the top five scores, while positions such as tailback, wide receiver and cornerback rank at the bottom.