Laying on the underdog in a horse race with a view of a later green-up
These triggers are based on the natural inclination of bettors to underestimate the highest priced horse (the underdog) in a race with an obvious favourite. There is a tendency for the prices of underdogs in such races to slightly raise towards the start of the event. If you lay beforehand, you may take advantage of this rise and green up in most cases (see an example of a statement in the end of the example).
So you pick a race where the favourite has odds less than 4.0 (you can set this in the constants) and lay on the horse with the highest price. As soon as it is possible, you green up for a profit of at least 3 ticks.
If the market goes in the wrong direction, you distribute the loss evenly when it's 3 minutes past the scheduled start or when the market turns In-Play.
Adjust your triggers using the following constants:
mins_before_start - When to start betting, minutes before the scheduled start;
sl_mins - When to distribute the loss, minutes after scheduled start;
max_liab - Maximum liability for the lay bet;
greenup_tcks - Number of ticks for green-up offset;
max_fav_price - Maximum price of the favourite.
An obvious drawback of this strategy is the high liability of your initial lay bet (due to the high prices of underdogs), although you compensate it eventually with a back bet, so your ultimate liability will only be a fraction on that high figure. Keep your default bets small and place a cap on your liability using the constants, if needed.
The triggers are set up to ignore races where the gap between the underdog's back and lay prices is greater than 2 ticks.
This statement is a result of the above triggers applied to 22 qualifying races that took place on 28/04/2015 (through backtesting in Time Machine).