https://fivethirtyeight.com/features/hating-gerrymandering-is-easy-fixing-it-is-harder/
The difficulty in defining what qualifies as a gerrymander is why states with bipartisan redistricting commissions end up generally being successful. i.e. if no plan can pass without buy-in from both parties, then it doesn’t matter what sort of crazy gerrymandering strategies are invented – as long as the other party’s not completely clueless, they can block it.
The redistricting commissions aren’t perfect – their biggest flaw is that they’re not constitutionally protected, and if one party controls the government, they can simply disband the commission by party-line vote, and revert to the old system. But aside from that, it’s the difference between bipartisan and nonpartisan. If both parties benefit from disenfranchising a population (say, a geographically concentrated third party), then nothing about the design of the redistricting commission would stop it. And shenanigans are still possible, albeit at a much more subtle level. That said, they are so much better than the systems used in most states, I’m in favor of them.