The reason the pilot can't do a straight in approach to 1R is because of sweeney ridge, which is right next to the approach path of 1R. (See map above) The approach is so rare that there is no official approach plate for it, however some have created fictional arrival plates:
A Swiss 777 performing the Circle to land
A United 757 landing
The approach shares a strong resemblance to the good old Kai Tak approach in Hong Kong, since aircraft arriving have to take a sharp turn extremely low to the ground over the city of Millbrae. This is why some call the approach "The Californian Kai Tak". Planes as big as the A380 and 747 have been seen performing this approach.
All in all, this is a super cool approach not many people know about.
Kind Regards,
Delta5142