In Mycalcs, under the System menu i think, the far right menu where where you find BRrank & PRrank etc, there is a rating called Inrun. If you create a mycalc to display the Inrun rating, you can then run a system for the Inrun mycalc top rated horse.

Basicly the top rated is expected leader. I was looking at Metro only, every horse had at least 4 starts. Is quick to run. I was just looking at it once and with some sensible filters returned a profit. I see they went poor in April though