>>47139790Charge Move Priority
Since everything is actually turn-based tied to in game time, there are moments where you and your opponent will both use charge attacks at the same time.
When this happens, the attacker with the higher raw attack stat will use their charge attack first.
This is why you always want 15 attack in Master League, and can sometimes get by with 1 or 2 attack IVs in lower cups so long as your level will be the same (or your attack will be slightly higher) as higher stat product/rank or "lower attack" mons.