This is a favourite of newbies, but it’s not very strong versus a player who knows the trick. Basically, despite the obvious temptation for orange to play on the bottom on move 2, DON’T DO IT. Be more patient, & set up the nice 1-3-2 series of holes off the central N. This is my invariable response when violet tries to circle round the bottom, & if it’s played right then it usually wins.
Note that orange’s main concern here is that if violet’s attack persists below, then if orange keeps circling above he will start to mess up his own trap laid for violet (the 1-3-2 series) by moving into that area. It’s essential to prevent this from happening by keeping a distance between the attacks & by blocking violet’s progress below before it gets too serious. And it’s important not to give violet the opportunity to block the leak in the centre before orange can play the 1.
If violet blocks on top rather than playing the Z5 this can be trickier for orange, but usually at worst it’s a 1-point loss for orange.