What nationwide redistricting rules would benefit Republicans the most?

[Libertas Vel Mors]

It's well-known that proposals such as the efficiency gap would favor Democrats, but there's been comparatively little research into what similarly "neutral" proposals would benefit Republicans. If Congress were to pass anti-gerrymandering legislation, what rules would be the best to pass for an R Congress?

[Libertas Vel Mors]

This thread has had some good discussion. It seems there's something of a consensus that commissions often favor Democrats. For posters who believe the above, what alternative redistricting method would you prefer? (Ie, if you had to design a model like Sol did, what would you go for?)