I run multiple systems.
Over multiple markets.
A few months ago I added a new system.
To trial within my portfolio.
The numbers were good.
A nice profit year on year.
I ran it with a small bank.
Recently my data provider said some of their data had been miscalcuated.
My YoY winning system.
Turned in to a YoY losing system.
Fortunately I was still in test mode.
So only risked a small bank.
No matter what the data says.
What your backtesting suggests.
There’s always risk.
This system was sports markets.
Always trial any new system.
- Is your data correct 100%
- Variance in past prices vs prices you can realistically get going forward
- Data provider has tech issues
- You miss some trades
- IT issues
- Betfair / trading partner issues
- Not getting matched / fully matched
- Human error
Always build variance in your systems.
Whatever my backtesting says.
I always reduce potential profits by 25%.
Negates the random issues you will encounter.