How valuable are scrambling QBs?

How much extra fantasy value, if any, does a top scrambling QB like Robert Griffin III offer? Matthew Emmons/US Presswire

One of the biggest fantasy football stories of the 2012 season was the advent of the read-option quarterback. This instantly gave leagues a fairly deep set of dual-threat options and changed the way owners approach draft-day strategies, keeper choices and auction bids.

A potential 2013 season impediment for these owners is that every NFL defensive coordinator is working overtime to find ways to slow down or stop the read-option in its tracks.

Those labors bring up a quandary in dealing with mobility value, as that trait generally is divided into two areas: productivity on planned plays, and productivity on unplanned plays, which in this case are most often scramble-type plays.

Because the coordinators will concentrate most of their efforts on stopping the planned plays, how much added value will the scramble plays end up offering these fantasy owners? Will it be enough to warrant paying the extra cost for this skill set, or is it a price too high to pay for the expected return on investment?