So, I did some quick work to show what the Rams could do, at a minimum, to help predict where Rapp might be picked. This involved combining the teams Rapp visited pre-draft and team needs(for speed used the PFF draft needs).
PFF draft needs
[
www.profootballfocus.com]
Rapp Pre-Draft visits
[
walterfootball.com]
So, the Rams have the 31st pick and are deciding what to do. Let's look at the picks after 31--these are the original teams holding the draft picks. Predicting trades seems like a futile exercise. What we are interested in is teams that are interested in Rapp(visit) and have a need for Rapp's position(more likely to value him higher).
The teams that visited with Rapp with a pick between 31 and 61:
Bucs
Cardinals
Cowboys
Giants
Lions
Panthers
Patriots (x2)
Raiders
Seahawks
Steelers
That's 11 possible draft slots.
The teams and picks that both had a visit with Rapp and a need at Safety are below:
Bucs 39
Panthers 47
Even if we assume the draft needs are incorrect and add 3 more teams to the Safety needs list that is 5 possible spots for Rapp to go. 5 out of 30 picks. And the Rams have the benefit of adjusting on a pick by pick basis. Not to mention other sources of inside intel.
Another factor is the concensus positional ratings--Adderly was higher ranked than Rapp most everywhere. They are different players and imo play different positions but let's assume Adderly was ranked #1 by most and Rapp #2 or lower. With Adderly still on the board the Rams probably feel even more confident. Adderly visited the Bucs, Giants, Seawawks and Lions. I don't think it is coincidence that Rapp was selected immediately after Adderly was picked.
If you take the information that is publicly available, do the work to put it together, and have some risk tolerance you can definitely profit. 2 Safeties were taken between picks 31 and 60. Blair and Adderly.