How is Overall Run IQ Score Calculated?

Your user manual states that your overall run IQ is based on a median of your best 8 turns done in a row. I have looked through multiple sets of data(mine and others) and cannot figure out how the overall run score IQ is determined. It is not a median score of individual turn IQs as stated in the user manual. It would be very helpful to understand how the overall rating IQ is determined. I have observed individual data showing 6 turns scored above 155 IQ with the bottom 2 turns scoring at 153. The overall IQ for that run was 153? For the more technically inclined people out there it would be nice to understand how and why we are given certain scores. As an engineer it is very frustrating to not be able to make sense of the data and correlate it to overall scores. Maybe an update to the user manual is in order with an actual explanation of how overall scores are calculated? Or at least an explanation of what data points are being used for the score and why? Thanks