Growing up in Ireland, the front brake was always on the right. I've always assumed that this was a UK standard, but I'm pretty sure most of the bikes on GCN are set up left-front. As I understand it, at some point the US mandated right-rear, the logic being that locking up the rear wheel and skidding was "safer" than locking up the front and going over the bars. My view is that, since the front brake does most of the braking, the hand with the most strength and modulation should operate that brake, so your dominant hand should operate the front, whichever side that happens to be. As a righty, all my bikes are set up right-front and always will be.