Overki11, the spine in rod is important because under load, the rod will naturally try to twist and roll to the softer "spine", so for a beachcasting multiplier rod, the rod will have a better feel to the cast if the guides are on the soft side. For a fixed spool pendulum rod, the guides go on the "hard" side, as the reel faces up on the power stroke. For a fixed spool backcasting rod, the guides are on the soft side, as the cast is made with the reel underneath the rod. For a multiplier backcasting rod, some casters have the reel facing up, and some underneath when setting up the cast, so it depends on which preference! For a downtide boat rod, the most strain the rod will be asked to do, is when hauling in fish, so the guides for a multiplier will go on the hard side of the spine, as the rod will not try to roll over in your hands under load.