I devised this method to randomize the Settlers of Catan board so that it was always different from game to game and fair because it was not created from my own input.
Land Tiles
With the land tiles facing down, shuffle them thoroughly. Turning them up one at a time, the first one is the center. Orient it so that a flat edge faces you. Lay subsequent tiles around the first clockwise. I start the two rings at the top position (12 o’clock).
Sea Tiles
Separate the sea tiles into piles for non-port, 3-fer ports and resource ports. Turn the 5 resource ports face down and shuffle them. Roll a single die. If the number is odd, place the top resource port to the left of the topmost land tile. If the number is odd, place the top resource port to the right of the topmost tile. Remember that port tiles should always be turned to face the longest land tile row. Now going around clockwise, place a non-port tile, a 3-fer tile, a non-port tile and the next resource tile. Repeat these around the perimeter of the board. The last resource tile will just have a non-port tile between it and the first resource tile placed.
Land Tile Numbers
The numbers that go on the land tiles have letters from A to R that designate the order of their placement. To get a beginning tile, roll a single die. The topmost land tile is “1” and the corners are numbered 1 through six going clockwise. Starting on the tile indicated by the die, place the numbers from A to R going clockwise. Do not place a number on the desert.