World Record Lego Great Ball Contraption Brickworld Chicago 2019 [video]

Great Ball Contraption (GBC) is a standard for building modular Rube Goldberg machines that continuously move LEGO soccer balls or basketballs from one GBC in-basket to the next using LEGO motors and programmable controllers: https://www.greatballcontraption.com/wiki/standard. This video from Brickworld Chicago last year has almost 400 GBCs with some impressively creative approaches.