AT, BL and CA can vary between 50% and 150% of the on-screen value.

To use your examples

i) 12 EN vs 8 AT = steal

8 AT can range between 4 and 12, so you were just unlucky that time.

ii) 7 EN vs 10 AT = 2 EN

10 AT can range between 5 and 15. Again, you were very unlucky.