Advanced Mechanical Advantage (MA) systems for River Runners... The Poldo Hitch or Voodoo Loop
We're all used to the "Z-Drag" 3:1 system. As I've taught in my swiftwater rescue classes for years, it should be the last thing you go to, but you need to know it blind when you're in a rush. Having said that, my go-to nowadays is the Voodoo Loop. Nearly as much MA, quicker and easier, & far less gear (2 biners & the rope). I teach it in my advanced courses, but here it is for all of you paddlers' boatification.
(Note: Despite the text in the Alpine Savvy site, this hitch does indeed provide MA, as noted in the very detailed analysis on the ITRS Online site.)