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# OnCalculatePerformanceValue()

## Definition

This method calculates the value for the Optimization Fitness.

## Syntax

`protected override void OnCalculatePerformanceValue(StrategyBase strategy)`

## Examples

```csharp
protected override void OnCalculatePerformanceValue(StrategyBase strategy)
{

     Value = strategy.SystemPerformance.AllTrades.TradesPerformance.Percent.Drawdown;

}
```