I've added a new trigger example with a video demonstration:
Collective GreenupThe main steps are:
1. Towards the start of a race, pick the third, fourth and fifth favourites and remember their odds.
2.When their cumulative odds drop by a given percentage, Dutch-Lay them to a fixed liability. By the drop of cumulative odds I mean the change in their lay book%. E.g., if first they were priced 5.0, 7.8 and 12, then their book% was 100/5 + 100/7.8 + 100/12 = 41.15%. Now if all of them go down, or if at least some of those odds drop down enough to cover the raise of the other, then they will qualify for the Dutch. E.g. if the above prices changed to 4.8, 7.3, 16, the book% will be 40.78%, which means their cumulative odds decreased in spite of the growth of the third price.
3.Wait till there is an opportunity for a collective green-up. Such opportunity will occur when the sum of their potential tradeout P/L is positive.