If Team A averages 1600SCpts and Team B 1700SCpts what would you expect them to score when they played each other? I reckon 99/100 people would instantly think the obvious but wrong answer.
Because the two teams average 3300pts between them many people would presume the answer would simply be Team A 1600 v Team B 1700, which I also intuitively thought.
The best way to explain why that is wrong is by considering if Team B played Team C that averaged 1650SCpts. Team C would be by definition exactly average, so every side that played them would be expected to score their average as they are neither easier or harder to play against than average. So Team B would be expected to score 1700pts v Team C. Hence Team B would have to be expected to score more against a lesser team such as Team A.
The correct answer is Team A 1550 v Team B 1750. This is because Team A is 50pts easier than average to play against and Team B is 50pts harder than average to play against.
Using the right formula Team B would be expected to score:
1600 v a 1750pt team
1650 v a 1700pt team
1700 v a 1650pt team
1750 v a 1600pt team
1800 v a 1550pt team
Average = 1700, as it should be when playing 5 opponents averaging 1650pts on average.
Using the wrong basic ratio formula Team B would be expected to score:
1626.1 v a 1750pt team
1650 v a 1700pt team
1674.6 v a 1650pt team
1700 v a 1600pt team
1726.2 v a 1550pt team
Average = approximately 1675, which it clearly shouldn't be when playing 5 opponents averaging 1650pts on average.