Want to know if this trigger is doable

Thank you very much guys.
I almost finished the trigger setup.
I just need to work on the amount variable.

This is the setup and working for a horse by name:

Repeat - just once
Action - lay
Markets - win market
Market status - in-play
Execute - once per selection
Condition - selection name contains "Mike John"
Price - r_ticks(actual_sp/1.3,-1)
At in-play - keep;