How will gerrymandering measure up before the Supreme Court?

In less than a month, the U.S. Supreme Court will hear Gill v. Whitford, a politically charged gerrymandering case, and rule on whether Wisconsin's State Assembly map was intentionally drawn to favor one party over another. Called "the most important" case of the term by Justice Ruth Bader Ginsburg, the court's decision could be a death knell to partisan redistricting, transforming the way political districts have historically been drawn.

Even the most casual observer of the case is bound to stumble upon various methods of measuring gerrymandering, including the one used in this case — the widely cited "efficiency gap."

In the lower court trial, the efficiency gap held great sway, as its wasted votes aided the plaintiffs' case by ranking districting plans and flagging those plans that had likely been gerrymandered.

But it does not take long to realize that gerrymandering allegations have nothing to do with the efficiency gap, or its wasted votes. They have to do with seats and votes.

In Wisconsin's 2012 state assembly elections, Democrats received 50 percent of the statewide vote but only 40 percent of the legislative seats. Republicans fist-bumped and were congratulated for ekeing out a victory. Democrats' shoulders slumped as they claimed the system was gamed, all because the numbers favored Republicans.