Positionally, certain positions have a draft range that most fans don't consider. For instance, it's very rare for a G or C to go before the 20's, because the drop off from a good G/C to an average G/C isn't very big. There are simply a large supply of interior linemen who can do a decent job. OT on the other hand, requires a certain quickness that is hard to find in guys of that size, so those are rarer. Finding one quick enough to play LT with all the other things that all the other OL guys have too is very hard to find, thus the premium.
TE's suffer from the fact that many offenses substitute them out for another WR, so many aren't every down players. Most TE's coming out of college are glorified possession receivers or rocked up seam receivers. Finding someone who blocks effectively and adds the passing dimension like a Witten, Gonzalez or Vernon Davis is rare these days. Eifert is a receiver, but not a great blocker yet, so he'll probably go in the 20's somewhere. He's the best red zone threat in this draft--something we desperately lack--with 6'6, long arms, good vertical, and a wonderful ability to high point the ball, he catches over everyone. He is also probably the best catcher in traffic that this draft has as well.
If Eifert makes it into the 20's, I'd try to trade up from #42 to draft him. IMHO, he is not only a truly great player in a draft that ultimately will have a lot of busts, but also exactly what the Dolphins and Tannehill need.
