If you only lose 7v1's, your luck could be 0 cuz that will never happen. I don't think winning all your rolls in a game won't give you 100% luck either unless it were all 2v8 wins or something.

If you look at all your lost rolls there probably was something in it like a 4v3 lost attack. Well if that had been a 4v2 loss, your luck should have been even lower than 30, say 28%.

In theory, 30% just gives you an idea of how common it was to win/lose all the moves that were done that game (compared to the statiscal chances for each type of XvX roll).

Let's see if I am understanding. You are saying that if I lose 3v3 I am less unlucky that if I lose 3v4 and that difference in "luck" gets reflected in the luck percentage.

Is the luck just an average of probabilities P( A > D )?
where :
A is the number rolled by the attacker
D is the number rolled by the defender

no, what i actually was saying is that if you lose a 4v3, your luck will drop less compared to when you lose a 4v2. Wether you win or lose a 3v3 won't influence the luck% much as it is an XvX roll (45,4% for winning it).

However, winning a 3v3 should increase your luck% more then a second 3v3 that you lose will make it drop again. In other words, if you win 1 out of 2 3v3, your luck will slightly increase since it is supposed to be 454 out of 1000 and not 500 out of 1000.

Again, luck% should reflect how good or bad you are at beating the statistical odds for winning/losing all the rolls you were involved induring a game. It is just a formula, it doesn't incorporate other vital aspects of luck (rolls to cut or connect + period in the game when you lose say a 4v3 don't get taken into account as a crucial part of your luck%)