Tick-data quality: why '90% modelling quality' misleads you

That '90% modelling quality' bar you see in MT4 backtest reports is effectively a vanity metric. It usually just means the tester successfully interpolated price movements between M1 bars. It says nothing about the actual accuracy of the price path, the spread, or the slippage experienced during those minutes. If your strategy relies on scalping or tight stop-losses, this number is essentially noise.

Real tick data is a different beast entirely. It records every single bid and ask update as it happened in the market, rather than guessing what happened between two minute-bar snapshots. Relying on interpolated data often leads to 'overfitting' where your backtest looks perfect because the engine invented favorable price action that never existed.

If you want to move toward something more reliable, you need to import historical tick data. Here are the common sources practitioners use to clean up their backtesting:

• Dukascopy: Offers free historical tick data exports that are generally considered the industry standard for retail FX.
• Tick Data Suite: A tool like Tick Data Suite that integrates directly with MT4 to feed real tick data into the tester.
• Tick Story: Another common utility for managing and exporting tick data for backtesting purposes.

Keep in mind that even with perfect tick data, you are still dealing with historical conditions. You cannot model the order flow or the liquidity depth that existed at that exact moment. You are always guessing at how the market would have filled your specific order. Are you testing your strategy against real tick data, or are you still relying on the default MT4 interpolated bars?