what is 3 move opening? MONSTER double round robin championship section

The first English version championship just started, and it is very unusual....

draughts.cv.ENG.1.1.1

First of all, it is a double round robin, unprecedented (?) in any championships at littlegolem, And it is a monster, 15 players, so a total of 28 games!!  Secondly, all the games start at move 4 instead of move 1....and every game has the comment to start the game "3-move opening".  I guess it is impossible to resign these 28 games, as it is past move one, a player would lose a bunch of rating points.

I am not a fan of forced opening play.  Let us just play the first three moves ourselves?  What is the point?

This is common practice in high level checkers tournament play.