The seven-over-four ratio: seven equal units across four matras, sitting between the 3:2 layer and double rate. Like kuad it realigns with the cycle only at long intervals, so the player must hold a fully independent internal grid.
Biad rarely appears as a headline effect; more often it surfaces inside tihai calculations and Punjab- and Ajrada-style development, where a phrase's internal rate bends against the count before resolving. It is usually the last of the standard ratios a player masters.