Border security is a hot topic in geopolitics at present, and it might be top of mind for WA trainers too as visiting stables shoot for their first clean sweep of the state’s “big three” races in 15 years.

The win of dinki-di Knight’s Choice in the Melbourne Cup might have alleviated anxiety about the foreign takeover of our greatest race, but out west you don’t have to come from overseas to be regarded as an enemy alien.

The last time visiting stables took all three was 2009, when the Tracey Bartley-trained Sniper’s Bullet took the Railway and Kingston Town while the Tony Noonan-trained Ortensia won the Winterbottom.

In fact, a visitors’ clean sweep of WA Group 1s has never happened, because the Winterbottom wasn’t promoted (at the expense of the WA Derby, run in autumn) until 2011.

It’s looming as a real possibility this time, however. Annabel Neasham and Rob Archibald took the Railway with Port Lockroy, Bjorn Baker won the Winterbottom again with Overpass and three of the top four in betting for this Saturday’s Northerly are trained in the east.

Standing in the invaders’ way is the filly Storyville, who is aiming to become the Williams stable’s fifth Northerly winner.

Notably, two of the team’s four winners have been fillies (Perfect Reflection in 2015 and Arcadia Queen in 2018), as have four of the past nine Northerly winners overall.

Indeed, three-year-olds have a remarkable record in this race —19 wins in 48 years.

There are few if any open-age Group 1s on the Australian calendar where three-year-olds boast a similar record.

In the 11 years since Shamus Award won the 2013 Cox Plate as a maiden, just five three-year-olds have won an open-age Group 1 beyond 1600 metres, and they’ve all done it in the Northerly.