extern double     MaximumRisk       =0.02;   //%account balance to risk per position
extern double     DecreaseFactor    =3;      //lot size divisor(reducer) during loss streak
extern double     Lot.Margin        =50;     //Margin for 1 lot 
double LotsOptimized()  
{
   double lot;
   int    orders=HistoryTotal();
   int    losses=0;
   lot=NormalizeDouble(AccountFreeMargin()*MaximumRisk/Lot.Margin,2);
   if(DecreaseFactor>0) 
{
      for(int i=orders-1;i>=0;i--)  
{
         if(OrderSelect(i,SELECT_BY_POS,MODE_HISTORY)==false)
 { Print("Error in history!"); break; }
         if(OrderSymbol()!=Symbol() || OrderType()>OP_SELL) continue;
         if(OrderProfit()>0) break;
         if(OrderProfit()<0) losses++; }
      if(losses>1) lot=NormalizeDouble(lot-lot*losses/DecreaseFactor,2);   }
   if(lot<0.01) lot=0.01;
return(lot);   }//end LotsOptimized