3x3x3 Blindfolded (3BLD or just BLD for short) is an official WCA event requiring one to inspect a Rubik's Cube and once the cube is fully memorized, solve it with a blindfold covering their eyes. The final time includes the time it takes to inspect and to solve added together. The solver may not have any view of the cube during the solving stage. In order to ensure that the solver is unable to see the cube during the solving phase, the judge typically places a sheet of paper between the solver's blindfold and the cube.
Old Pochmann is a simple and easy beginners 2-cycle BLD method, which solves for one piece at a time. The only algorithms needed in this method are the T PLL, Ja PLL, and the Jb PLL for the edges, the Y PLL for the corners, and the Ra PLL for parity. With commutators, the entire cube can be solved using these 5 PLL algorithms every time.
TuRBo is a 3-cycle BLD method which solves for two pieces at a time.
BH / 3-Style
BH, sometimes referred to as 3-Style, is an advanced 3-cycle BLD method which uses pre-memorized, move optimal, commutator 3-cycles for all possible 3-cycles starting from a fixed buffer location. For pieces where orientation is defined, the orientation and permutation of those pieces are solved simultaneously.