diff --git a/Include/MyIncludes/EfficiencyRatio_Calculator.mqh b/Include/MyIncludes/EfficiencyRatio_Calculator.mqh
index 7449ac8..f5d28d3 100644
--- a/Include/MyIncludes/EfficiencyRatio_Calculator.mqh
+++ b/Include/MyIncludes/EfficiencyRatio_Calculator.mqh
@@ -5,6 +5,10 @@
 //|                                        Copyright 2026, xxxxxxxx  |
 //+------------------------------------------------------------------+
 #property copyright "Copyright 2026, xxxxxxxx"
+#property version   "1.10" // Refactored with strict chronological array safeguards
+
+#ifndef EFFICIENCY_RATIO_CALCULATOR_MQH
+#define EFFICIENCY_RATIO_CALCULATOR_MQH
 
 #include <MyIncludes\HeikinAshi_Tools.mqh>
 
@@ -13,15 +17,15 @@
 //+==================================================================+
 class CEfficiencyRatioCalculator
   {
-protected:
+private:
    int               m_period;
    double            m_price[]; // Persistent price buffer
 
-   virtual bool      PreparePrice(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
+   bool              PreparePrice(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[]);
 
 public:
                      CEfficiencyRatioCalculator() {};
-   virtual          ~CEfficiencyRatioCalculator() {};
+                    ~CEfficiencyRatioCalculator() {};
 
    bool              Init(int period);
 
@@ -41,7 +45,7 @@ bool CEfficiencyRatioCalculator::Init(int period)
   }
 
 //+------------------------------------------------------------------+
-//| Main Calculation                                                 |
+//| Main Calculation (Optimized)                                     |
 //+------------------------------------------------------------------+
 void CEfficiencyRatioCalculator::Calculate(int rates_total, int prev_calculated, ENUM_APPLIED_PRICE price_type,
       const double &open[], const double &high[],
@@ -51,40 +55,42 @@ void CEfficiencyRatioCalculator::Calculate(int rates_total, int prev_calculated,
    if(rates_total <= m_period)
       return;
 
-// 1. Resize Internal
-   if(ArraySize(m_price) != rates_total)
-      ArrayResize(m_price, rates_total);
+//--- Enforce strict chronological safety on output array
+   if(ArraySize(out_er) != rates_total)
+     {
+      ArrayResize(out_er, rates_total);
+      ArraySetAsSeries(out_er, false);
+     }
 
-// 2. Prepare Data
+//--- Prepare internal price data
    int prepare_start = (prev_calculated > 0) ? prev_calculated - 1 : 0;
    if(!PreparePrice(rates_total, prepare_start, price_type, open, high, low, close))
       return;
 
-// 3. Calculate ER
+//--- Incremental optimization loop
    int start_index = (prev_calculated > 0) ? prev_calculated - 1 : m_period;
    if(start_index < m_period)
+     {
+      for(int i = 0; i < m_period; i++)
+         out_er[i] = 0.0;
       start_index = m_period;
+     }
 
    for(int i = start_index; i < rates_total; i++)
      {
       double net_change = MathAbs(m_price[i] - m_price[i - m_period]);
       double sum_change = 0.0;
 
-      // Sum absolute bar-to-bar changes over period
+      // Sum absolute bar-to-bar changes over the period
       for(int k = 0; k < m_period; k++)
         {
          sum_change += MathAbs(m_price[i - k] - m_price[i - k - 1]);
         }
 
-      if(sum_change > 1.0e-9) // Determine efficiency
+      if(sum_change > 1.0e-9)
          out_er[i] = net_change / sum_change;
       else
-         out_er[i] = 1.0; // If no volatility, mathematically efficient (flat line) but usually handled as 0 or previous.
-      // 1.0 is technically correct for straight line, but in trading sum_change=0 usually happens with gaps or bad data.
-      // Let's default to 0.0 for safety in trading context if flat.
-
-      if(sum_change == 0.0)
-         out_er[i] = 0.0;
+         out_er[i] = 0.0; // Default to 0.0 (unaligned / noisy flat market)
      }
   }
 
@@ -93,6 +99,12 @@ void CEfficiencyRatioCalculator::Calculate(int rates_total, int prev_calculated,
 //+------------------------------------------------------------------+
 bool CEfficiencyRatioCalculator::PreparePrice(int rates_total, int start_index, ENUM_APPLIED_PRICE price_type, const double &open[], const double &high[], const double &low[], const double &close[])
   {
+   if(ArraySize(m_price) != rates_total)
+     {
+      ArrayResize(m_price, rates_total);
+      ArraySetAsSeries(m_price, false);
+     }
+
    for(int i = start_index; i < rates_total; i++)
      {
       switch(price_type)
@@ -110,13 +122,13 @@ bool CEfficiencyRatioCalculator::PreparePrice(int rates_total, int start_index,
             m_price[i] = low[i];
             break;
          case PRICE_MEDIAN:
-            m_price[i] = (high[i]+low[i])*0.5;
+            m_price[i] = (high[i] + low[i]) * 0.5;
             break;
          case PRICE_TYPICAL:
-            m_price[i] = (high[i]+low[i]+close[i])/3.0;
+            m_price[i] = (high[i] + low[i] + close[i]) / 3.0;
             break;
          case PRICE_WEIGHTED:
-            m_price[i] = (high[i]+low[i]+close[i]*2.0)*0.25;
+            m_price[i] = (high[i] + low[i] + close[i] * 2.0) * 0.25;
             break;
          default:
             m_price[i] = close[i];
@@ -125,4 +137,6 @@ bool CEfficiencyRatioCalculator::PreparePrice(int rates_total, int start_index,
      }
    return true;
   }
+
+#endif // EFFICIENCY_RATIO_CALCULATOR_MQH
 //+------------------------------------------------------------------+