Hi
The previously posted trigger file was intended for use in triggers as a live user variable.
The attached trigger file will write the lowest achieved back price for the named selections to the program log at the end of the race.
You specified "is in list", so I have included that condition in the trigger. You will need to update the list with your own selection names.
The trigger uses the variable minbp_{minutes} which records the minimum back price over the time {minutes}. I have made the {minutes} a constant, so it is easy to change. Assuming you start monitoring markets about 1 min before the start, 10 minutes should cover most races, but you may need to experiment with this.
The trigger writes the minimum back price to the program log when the market is settled, so you should not delete finished or settled markets.
Attached please find the trigger file and a sample output to the program log.