Ernie,
Very sorry it took a few days to respond to this. Here is an extract from the
Release Notes for Beta 2, Page 3, describing the different PSS (Paceline Selection Strategies):
PSS: Population Sample. An experimental Strategy based on 2nd Call PoH Adjusted Velocity. Based on the number of lines in a horse’s PPs, the line with the 1st or 2nd or 3rd best 2nd Call PoH velocity is selected. Experiment at your leisure ...
The book on applied statistical methods by Douglas Hubbard '
How to Measure Anything' suggests how to find a representative range of values for a collection of items (a large or small collection) by taking a limited sample of the larger population. The sample taken depends on an estimate of the size of the total population. The resulting estimate is supposed to be an accurate assessment of the likely range of values, with a degree of confidence approaching 90%.
A similar statistical measurement approach is used as a component of NewPace.
The
Population Sample PSS looks at the
2nd Call Velocity and selects the 'nth' ranked 'high' value depending on how many pacelines are available to measure. The 'low' value (representing the low range of the sample for each horse) is omitted.
For 9 or more lines, it selects the 3rd highest
For 6-8 lines, it selects the 2nd highest
For less than 6 lines, it selects the highest
In your example above, all the horses had 9 or more valid pacelines, so the rank of 2nd Call Velocity chosen for each horse was
3rd. This accounts for why the checked line always identifies the Yellow coloured 2nd Call (3rd ranked). The
1st ranked 2nd Call Velocity would only be selected when there are 5 or less valid pacelines.
You mentioned the 'All Horses' setting versus the 'This Horse' setting on the PSS window: this merely tells the PSS module to find a line either for the current horse you're looking at, or for All the horses in the race. The same PSS rules apply regardless.
I hope this clarifies what is going on. Good luck with your research!
Ted