On a FanDuel slate every FD Upload button writes FanDuel's columns (QB, RB, RB, WR, WR, WR, TE, FLEX, DEF) using the player ids from the API — nothing to load.

Pick up to 12 anchor players and how many lineups to build around each. For every anchor the builder searches lineups that contain him and keeps the highest-projected ones — the Showdown Wheel's captain concept applied to Classic. Sim Lineups uses the same anchors but picks at random: it simulates lineups around each anchor (drawn by predicted ownership, kept only if they pass the tier screen, QB stack, no offense vs your DST and a 97% salary floor), drops the bottom of the list by projection (Sim draw from) and takes one at random from each equal section. Games, TD odds, team caps, max games and bring-back in Games & Correlation above all apply.

Pick the players you want in — up to 3 QB · 6 RB · 8 WR · 3 TE · 3 DST. You can leave spots open: every slot your picks don't fill is filled at random from the eligible players, under the cap, and each lineup is stacked with a pass-catcher from its QB's team. Build makes that many lineups.