Staking never been about luck, even when if you and your opponent die at the same time, There's something and it's about the last player who attacked first, which who hit first, I tested this one and i found a something that,
If you click the first accept of the duel arena challenge, when the duel arena system move both players to the main duel there's a count down which it will be 3-2-1, I realized that if you accept the first screen before your opponent without accepting the second one which letting your opponent accepting first you will start attacking first, Unless you spam clicking on your opponent before the count down ends, then you and your opponent will start at the same time, but if you click one time "Attack" before the count down ends you will start hitting first
Another thing if you accept the second screen without accept the first one which your opponent accepts it first, He will start hitting your first when the count down in the main duel start,
I can keep explaining more and more about it, But what the point of this, It happens 1/100 times so you don't have to understand what i actually said above.