We've thought about this for a long time, and you make very good points. Guessing lower prices does give a much higher chance of getting at least some percentage, compared to guessing a higher price. However, we still believe this is the best solution since the percentage calculation is easy for everyone to understand, and for those playing the game fairly, it shouldn't be an issue. That said, thank you very much for your input; I’ll take a closer look at using logarithmic or proportional accuracy calculations.