Haven’t seen the question asked in this manner. What legit and legal strategies do people use, whether axis or allies, annoy you the most?

The reason I ask is because like most games and sports the strategies are usually common.

When I’ve played my brother in law in axis and allies he’ll often be the allies and he’ll stay away completely from japan with the US. he won’t commit a single solitary unit unless i threaten an attack on western US which has to be at least a 2 round plan.