diff --git a/src/Koogle.Web/Components/Game/GameInputPanel.razor b/src/Koogle.Web/Components/Game/GameInputPanel.razor
index 2a2271e..2da2214 100644
--- a/src/Koogle.Web/Components/Game/GameInputPanel.razor
+++ b/src/Koogle.Web/Components/Game/GameInputPanel.razor
@@ -171,6 +171,13 @@
     private void HandlePinClick(int pinNumber)
     {
         var currentStatus = GetPinStatus(pinNumber);
+
+        // In Decrease mode, fallen pins cannot be reset to standing
+        if (GameState.Value.ThrowPanel.ThrowMode == ThrowMode.Decrease && currentStatus == PinStatus.Fallen)
+        {
+            return;
+        }
+
         var newStatus = currentStatus == PinStatus.Standing ? PinStatus.Fallen : PinStatus.Standing;
 
         Dispatcher.Dispatch(new SetPinStatusAction(pinNumber, newStatus));
@@ -246,18 +253,25 @@
         if (newThrowPanel.ThrowCounterPerRound >= newThrowPanel.ThrowsPerRound)
         {
             newThrowPanel = newThrowPanel with { ThrowCounterPerRound = 0 };
-
-            // Reset pins if in Reposition mode
-            if (newThrowPanel.ThrowMode == ThrowMode.Reposition)
-            {
-                newThrowPanel = newThrowPanel.ResetPins();
-            }
+            // Reset all pins at end of round (both modes)
+            newThrowPanel = newThrowPanel.ResetPins();
         }
         else if (newThrowPanel.ThrowMode == ThrowMode.Reposition)
         {
             // In Reposition mode, always reset pins after each throw
             newThrowPanel = newThrowPanel.ResetPins();
         }
+        else if (newThrowPanel.ThrowMode == ThrowMode.Decrease)
+        {
+            // In Decrease mode: Mark fallen pins as disabled (not available for next throw)
+            newThrowPanel = newThrowPanel.MarkFallenAsDisabled();
+
+            // If all pins are down, reset all pins for a fresh set
+            if (newThrowPanel.AllPinsDown())
+            {
+                newThrowPanel = newThrowPanel.ResetPins();
+            }
+        }
 
         // Dispatch record throw action
         Dispatcher.Dispatch(new RecordThrowAction(newThrowPanel, GameState.Value.GameModel));
diff --git a/src/Koogle.Web/Store/GameState/GameState.cs b/src/Koogle.Web/Store/GameState/GameState.cs
index a2312c0..3b20b07 100644
--- a/src/Koogle.Web/Store/GameState/GameState.cs
+++ b/src/Koogle.Web/Store/GameState/GameState.cs
@@ -257,6 +257,27 @@ public record ThrowPanelState
         9 => this with { Pin9 = status },
         _ => this
     };
+
+    /// <summary>
+    /// Marks all fallen pins as disabled (for Decrease mode).
+    /// </summary>
+    public ThrowPanelState MarkFallenAsDisabled() => this with
+    {
+        Pin1 = Pin1 == PinStatus.Fallen ? PinStatus.Disabled : Pin1,
+        Pin2 = Pin2 == PinStatus.Fallen ? PinStatus.Disabled : Pin2,
+        Pin3 = Pin3 == PinStatus.Fallen ? PinStatus.Disabled : Pin3,
+        Pin4 = Pin4 == PinStatus.Fallen ? PinStatus.Disabled : Pin4,
+        Pin5 = Pin5 == PinStatus.Fallen ? PinStatus.Disabled : Pin5,
+        Pin6 = Pin6 == PinStatus.Fallen ? PinStatus.Disabled : Pin6,
+        Pin7 = Pin7 == PinStatus.Fallen ? PinStatus.Disabled : Pin7,
+        Pin8 = Pin8 == PinStatus.Fallen ? PinStatus.Disabled : Pin8,
+        Pin9 = Pin9 == PinStatus.Fallen ? PinStatus.Disabled : Pin9
+    };
+
+    /// <summary>
+    /// Checks if all pins are knocked down (fallen or disabled).
+    /// </summary>
+    public bool AllPinsDown() => GetPins().All(p => p != PinStatus.Standing);
 }
 
 /// <summary>