The off-leash area near Albert Park Lake has, according to its regulars, always had unwritten rules. Dogs are introduced nose-first. Owners don't hover near someone else's lead. And balls are thrown in a long, low, overarm arc that lets dogs see the full flight path, rather than the sidearm skim that sends them scrambling sideways into other people's picnics.

Priya Ramesh didn't know any of this when she moved to Mills Street in June with Scout, a two-year-old border collie with, by her own admission, an above-average interest in balls. For three weeks, Priya threw sidearm, the way she'd thrown since high school softball, sending Scout veering unpredictably across the oval and once into a stroller. Nobody said anything directly. Instead, the regulars, a loose group of six who meet most mornings near the fenced corner by the lake path, began arriving earlier, moving slightly further away, and referring to Priya, within her hearing, as "sidearm."

The freeze-out lasted into August, when Priya, tired of being the park's cautionary tale, turned up with a plastic ball launcher, the kind that flings a tennis ball fifty metres with one flick of the wrist. Scout's retrieval radius tripled overnight. Within a fortnight, two of the six regulars had bought their own launchers. A third refused on principle, calling it "outsourcing the bond," which caused a rift inside the group far larger than any sidearm throw ever had.

By September, the Albert Park dog park had effectively split into a traditional throwing faction and a launcher faction, each with its own patch of oval and its own opinions about the other's dogs. Priya, the woman they'd frozen out in June, now leads the launcher faction by simple seniority, since she was the first to own one. She says she has no interest in reconciling the two groups and has started arriving at 6:45am specifically to claim the better patch of grass before the traditionalists do.

The council, which maintains the off-leash signage, has not been asked to intervene and has indicated it would decline if it were.