Last week a member emailed us a question. He wanted to find trainers whose horses were running well — beating most of the field — without actually winning. Yards, in other words, whose form the results column has not caught up with yet.
It was a good enough question that it is now a feature. Two new filters have gone live in the System Builder: Trainer PRB % (14d) and Trainer PRB % (28d).
What Trainer PRB measures
PRB is the percentage of rivals beaten. A horse that finishes third of ten beats seven of its nine opponents, so its PRB for that run is 77.8%. It is a more granular measure than a strike rate, because it credits a horse for running well in defeat instead of scoring every non-winner as a nought.
Trainer PRB applies that idea to a whole yard. It is the average percentage of rivals beaten by every runner the stable has sent out in the last 14 or 28 days. Above 50 means the yard's horses are generally finishing in front of more than half the field — running well, whatever the win column says. The 14-day window is the standard punting yardstick for a stable in form right now; the 28-day window smooths out the smaller yards that might only have a handful of runners in a fortnight.
Both figures are computed strictly from racing before each race day, so a back-test sees the number the yard actually had that morning. There is no hindsight in it.
The recipe — and an honest word about it
The member's question becomes three rules: Trainer PRB % (14d) of 55 or more, Trainer SR % (14d) of zero, and Trainer Runs (14d) of at least four. That is: the yard is beating most of the field, has not had a winner in a fortnight, and has run enough horses for the number to mean something.
Run it back to 2018 and it matches around 30,000 runners. Those runners do win more than their share — an impact value of 1.11. But the System Builder's own verdict on the system is blunt, and worth repeating: A/E comes out at exactly 1.00. Market par. The prices already know which yards are in form, and they have adjusted accordingly.
So this is not a system to back blind. It is a sharpener. Layered over rules you already trust — a class drop, a trip change, a course record — it answers a different question: of the runners that already interest me, which come from a yard that is firing right now? The Trim tab will tell you what it adds to any system you already have.
Before racing, too
Because the window is rebuilt each morning, Trainer PRB works on today's card as well as on history. Load the system, open the Qualifiers tab, and you get today's runners from yards in exactly that state — listed before the off, with the option to have them emailed.
Trainer PRB % is live now in the System Builder's Connections group for Proform Premium members.
And if you have a question the tools cannot answer yet, tell us. This one took a fortnight to become a filter.
