Actually I ran some numbers, and made a weighting that yielded roughly the same amount of PP for the typical player, tested with actual PP numbers.
I used =(COS(X/12,5)+1)/2 with this weighting the top25 performances would be weighted higher than they are now, below the top25 they would be weighted lower, and reach 0 around the top40th performance. I might have made mistakes when it comes to the actual numbers, but you get the idea.
This would mean that having lots of average performances wouldn't be as valuable, as having good ones in the top spots, and having an outstanding Top1 performance wouldn't be as important as it is now.
Blue line shows the current weighting, Red line is the one suggested.
I used =(COS(X/12,5)+1)/2 with this weighting the top25 performances would be weighted higher than they are now, below the top25 they would be weighted lower, and reach 0 around the top40th performance. I might have made mistakes when it comes to the actual numbers, but you get the idea.
This would mean that having lots of average performances wouldn't be as valuable, as having good ones in the top spots, and having an outstanding Top1 performance wouldn't be as important as it is now.
Blue line shows the current weighting, Red line is the one suggested.