Hi
If you go to the grv site the form that has the most detail has in the top left hand corner the avg win time for track an distance.
An alternate method is to find the avg time of Todays race an avg stdev for the field an multiply the std by zscore 1.60 an deduct this figure from the avg win race win time.

If you look at the zscore table you will notice that in that range of -1.6 to 1.6 95% of all performances will fall within this range, when runners win they normally record a time in the top 5% of their performance range, so thats why we multiply the avg stdev by 1.6.