Between 3 and 9 October 2026 we put the System Builder through its biggest test yet: every combination of its filters, on every UK and Irish race from 1 October 2023 to 30 September 2026. That came to 1,014,805,847,556 backtests, just over a trillion.
Here is what that involved, how big a trillion really is, and the 410 systems we have saved in the System Builder for you to use.
What we searched
We started with every UK and Irish runner from 1 October 2023 to 30 September 2026: 399,362 runners. We searched all runners, the free tips (39,251 picks) and each LLM model's picks.
170 settings
For all runners there were 170 individual settings:
- Race type, race class, race value, field size and every course with at least 100 settled runners.
- Official rating, OR move since the last run, price ranges and Favourites only or non-favourites.
- Value only and the minimum value edge.
- All 28 form and trainer or jockey angles in the builder.
Every combination, at any depth
We tested every combination of those settings, taking at most one from each group, at any depth. A combination was dropped only when it fell below 100 settled bets. Adding a setting can only shrink a system, so nothing above that floor was skipped. The deepest combinations had 22 settings at once.
On top of every combination we tested every Max picks per day rule: 1 to 10 picks a day, ranked by each of 12 fields.
410 systems saved for you
From all of that, we have saved 410 systems in the System Builder. Each one was picked for the steadiest level-stakes profit at Betfair SP with at least 100 settled bets:
- 84 systems: the best at each course.
- 202 systems: the best at each course and race type, such as Chepstow chases or Kempton all-weather races.
- 24 systems: the top systems across all courses over three years.
- 100 systems: the top systems across all courses over the last 12 months.
How to use them
Open the System Builder and filter the list by today's courses, course, race type, source or type. Every card shows its backtest: the bets, the dates and the level-stakes profit at Betfair SP and at SP. Try this system opens its rules so you can change them and test again.
None of the saved systems uses the Starting price or Favourites only filters. Those use the SP, which is only known once the race has run. Every figure is a backtest on past races, and past results do not guarantee future returns.
Frequently asked questions
How many System Builder combinations did you test?
1,014,805,847,556 backtests covering UK and Irish racing from 1 October 2023 to 30 September 2026. The biggest search ran twice at two price assumptions, so counted once each that is about 508 billion different combinations.
Are these figures before commission?
Yes. The System Builder shows level-stakes profit at Betfair SP and at SP, gross of exchange commission.
This article explains a method; it does not guarantee a return. Read the responsible gambling guidance and never chase a loss.