Metro is one of the rules Try Try Again, and is one the the six rules that follows the horse all the way through it's next five runs. I look at horses with a much narrower range than you've said, and they start lower than 5.

We have Qualifying set of filters that stay with us all through the five starts.

Start 1 - We back it

Start 2 - To back it we're looking for a poor run in it's previous start. There's really only one additional filter added here to the Q filters.

Start 3 - To back it we're looking for good form at it's previous 2 starts. There's two additional filters added here to the Q filters (Note; the additional filter added to Start 2 is removed)

Start 4 and 5 - We use only the original set of filters and it doesn't matter what the horse did in starts 2 & 3. The only changes to the Q filters are obviously the number of runs ('coz they've had a couple more since the Q run), and the number of runs from a spell for the same reason. Logic here is that the trainer still has the horse in work and must see something. Interesting to note that there's only a 20% drop in the number of selections from the Q run to the 5th run, it's a stat that surprised me and trust me I've checked and double checked this stat. Start 5 shows the best POT, and that too surprised me, and I've checked and double checked this too.

I've actually given you the lot here, don't bother asking about Start 2 & 3 contradicting each other, think about when and why we're having a bet.

I reckon there would be quite a few different scenarios that you could apply to get a very good set of Q filters that can be used to "follow" a horse for it's next few runs, with only a logical tweak here and there required.