so the summary of the stat system is
Step 1; You take 5 rolls and give us 5 sets of numbers
Step 2: We choose 3 sets of numbers
Step 3: One set is given to each of the characters
Step 4: The two primary attributes of the class of each character will get the two highest numbers in the set of numbers that that character got and the four remaining numbers in the set are given to the four remaining attributes. Those are the main numbers and X stands for them
Step 5: the number (X) will determine (+Y). Look at Attribute scores 
Attribute Scores:
1-2: -4 | 3-4: -3 | 5-6: -2 | 7-8: -1 | 9-12: 0 | 13-14: +1 | 15-16: +2 | 17-18: +3 | 19-20: +4
+Y is determined by how large the number (X) is. For example if the number is 10, which is between 9-12, you would see that +Y is 0

I just want to see if im correct on how the stat system works