Whilst I won't pretend to understand what your charts mean I think I know what you're trying to do, and I believe it will be a rollercoaster ride.
There will be races where you may have only the one winner ie the horse that despite its rank (wherever that may be) will be over the assessed price and not laid, and if it's right in the market the others will all be losers. Similarly I can see races where you only lay half the field.

Good luck with it but I can only stress (again & again & again) that bookies make their profits from the short end of the market, and every race is totally independent from every other race.

Thanks Mark
I hear you loud and clear. The chart is there for procedual advice only. The figures have no meaning other than having a figure in the cell. The figures are only the average SR for all horses in all criteria expressed as odds. The final figures will be totally different. My concern will be getting matched and whether any unmatched lays will automatically go to SP. I think that I have your message and intend to take it board. Beton

Firstly thanks for the advise given. I have given it the respect it demands. I was off in another paddock. I have finally analysed my data (43000 races) and made 11 charts each with 9 price ranges. This will be the base for future testing. Each is set up so that I can test laying for liability, variable liability, for a target amount or a varying target amount. I can now test on individual favorite, some favorites or all favorites. On the first chart I played with the variables and found that laying some of the field to a fixed even liability worked best. I made the remaining spreadsheets set to this model and found some anomalies. In some price ranges there were major losses in select field sizes and little niches which gave excellent profit. I found that by dumping 17% of the races I can make an acceptable profit on turnover with a simple basic system run on BBP. By dumping another 5% of races more profit could be gained but that would mean 3 different systems to be run concurrently.
Beton