Hi
I'm going to post a trigger for you that I use myself. I just need to change it a bit for you. The principle is:
Up to 1 min before the start
Back at lay price (better value, and less time to wait for green)
If there is gap and someone jumps ahead, the trigger will deal with that
When back matched, offer your lay bet (rather than wait), so you are in a better position in the queue
If back and lay matched, repeat until 1 min before off.
If 1 unmatched back inplay, allow 2mins to green or dist loss etc...