Can gerrymandering be measured?

Currently the Republicans have many more seats in the House than the Democrats, but the number of Democrat voters is larger. Something seems to be very wrong.

Thirty years ago the Supreme Court ruled that districts which are gerrymandered to favor one party over the other can be forced to be redrawn. But how do you prove it?

I just came across this article, which presents a relatively simple calculation to answer this question.

The basic idea is to determine the number of “wasted votes” of each party. For the party with a majority in a district, a wasted vote is any vote over 50%, which could in theory be used to win an election elsewhere. Similarly, for the party in the minority, all of its votes are wasted. Gerrymandering is interpreted as a deliberate attempt by one party to increase the number of wasted votes of the other. What is called the efficiency gap is just the cumulative difference across all districts between the wasted votes of the two parties divided by the total number of voters. The number is expressed as a percentage and some minimum value is used to indicate gerrymandering.

This seems to make sense to me, but I need to give it some more thought. If this measurement is considered reasonable, there will not need to be any more involvement by the Supreme Court. Each state would be free to use the efficiency gap to determine if redistricting is required.