Brookeborough if you establish each sectional standard to 100% it means that you would end up upgrading everything, because its implausible that a horse will run to par for every section. However with your method,
S1 - 95.06
S2 - 99.91
S3 - 103.35
This gives Hoss a STDEV.S of 4.16. If your numbers are in B4:B6 just enter =STDEV.S(B4:B6) and the number will pop up.
If you have 3 sections, the square root of this (SQRT) is 1.73, so the 4.16 / 1.73 to give 2.40.
The 2.4 is added to 100 to give 102.4 (102.4%) and the time of the horse is divided by that figure to increase its time. So you would be saying he ran the race in 69.69 / 1.024 = 68.06.
If all your S1-S3 sections amount to 100, you'd end up with a figure of zero and nothing to take away from the 102.4, hence why I prefer to set a general standard for efficient running.
The STDEV.P figure for all my efficient runners at Happy Valley over 6 furlongs at is 1.19 and I split Hoss a bit differently to you, as I am using 5 sectionals and got a figure of 1.75, so his 0.59 (1.75 - 1.19) is added to the 100 and I therefore say his efficient running time is 69.69 / 1.0059 = 69.28 which would be around a 6lb upgrade. If that figure is a minus we deem the horse has run efficiently and should be left with the figure he earned.
I'm also not sure if your figures are taking account of the percentage of the horse total time. Your three percentages for each horse should add up to 300 for this exercise, because you are dividing the time taken for the section per furlong by the time taken by the race per furlong.
So if in a 6 furlong race a horse runs in 66 seconds (three sections of 23, 21 and 22 seconds, the first section is (66/6)/(23/2). That is a 95.7 efficiency and that could look poor on its own, but if you've established that all the winning horses and those close up are all running to those fractions, you should regard that as a good figure. What I think you might be doing is establishing the performance of the horse relative to a par section instead.
View attachment 129815