Millennium Challenge 2002. That was a boondoggle. Yes the opposing force won and they had to reset the game but the OPFOR was up to some ridiculous shenanigans. For instance instead of using radios, which could be intercepted and tracked, they used motorcycles to convey messages…motorcycles that could travel at the speed of light.

Another piece of silliness is that there were commercial vessels (non-combatants) on the virtual water but OPFOR sometimes used them in ways that were impossible. As an example radar would return a 12 foot fishing boat and then that boat would launch four 20 foot long anti-ship missiles.

Then there’s whole idea of a CBG just hanging around shore for days on end staying inside a pre-determined box so that OPFOR always knew their location, something that almost certainly not happen in an IRL conflict.

The Commander of the Opposing Force was extremely clever but they needed a long list of nearly impossible to achieve advantages to make it work.