diff --git a/src/main/java/wordle/model/LetterCounter.java b/src/main/java/wordle/model/LetterCounter.java
index a24f39c4..21dea2dc 100644
--- a/src/main/java/wordle/model/LetterCounter.java
+++ b/src/main/java/wordle/model/LetterCounter.java
@@ -23,6 +23,11 @@ public void decreaseCount(Letters letters) {
         }
     }
 
+    public void decreaseCount(Letter letter) {
+        char value = letter.getValue();
+        letterCountMap.put(value, letterCountMap.get(value) - 1);
+    }
+
     public Letters filterCanDecreaseCount(Letters letters) {
         List<Letter> filteredLetters = letters.getLetters()
                 .stream()
@@ -32,7 +37,7 @@ public Letters filterCanDecreaseCount(Letters letters) {
         return new Letters(filteredLetters);
     }
 
-    private boolean canDecreaseCount(Letter letter) {
+    public boolean canDecreaseCount(Letter letter) {
         char value = letter.getValue();
         return letterCountMap.containsKey(value) && letterCountMap.get(value) > 0;
     }
@@ -46,7 +51,7 @@ public Letters filterCanNotDecreaseCount(Letters letters) {
         return new Letters(filteredLetters);
     }
 
-    private boolean canNotDecreaseCount(Letter letter) {
+    public boolean canNotDecreaseCount(Letter letter) {
         return !canDecreaseCount(letter);
     }
 }
diff --git a/src/main/java/wordle/model/TileService.java b/src/main/java/wordle/model/TileService.java
index b99a30fc..7420e992 100644
--- a/src/main/java/wordle/model/TileService.java
+++ b/src/main/java/wordle/model/TileService.java
@@ -1,5 +1,6 @@
 package wordle.model;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public class TileService {
@@ -30,14 +31,24 @@ private void processSamePositionAndValueLetters(Letters answerLetters, Letters i
         tiles.addGreenTile(samePositionAndValueLetters);
     }
 
+    // TODO: 알고리즘에 오류가 있어 급한대로 정상 동작하게 변경하였음. 다시 잘 생각해보자.....
     private void processSameValueLetters(Letters answerLetters, Letters inputLetters, LetterCounter letterCounter, Tiles tiles) {
         Letters sameValueLetters = inputLetters.findSameValueLetters(answerLetters);
-        Letters sameValueLettersForGrayTile = letterCounter.filterCanNotDecreaseCount(sameValueLetters);
-        tiles.addGrayTile(sameValueLettersForGrayTile);
 
-        Letters sameValueLettersForYellowTile = letterCounter.filterCanDecreaseCount(sameValueLetters);
-        letterCounter.decreaseCount(sameValueLettersForYellowTile);
-        tiles.addYellowTile(sameValueLettersForYellowTile);
+        List<Letter> lettersForYellowTile = new ArrayList<>();
+        List<Letter> lettersForGrayTile = new ArrayList<>();
+        for (Letter letter : sameValueLetters.getLetters()) {
+            if (letterCounter.canDecreaseCount(letter)) {
+                lettersForYellowTile.add(letter);
+                letterCounter.decreaseCount(letter);
+                continue;
+            }
+
+            lettersForGrayTile.add(letter);
+        }
+
+        tiles.addYellowTile(new Letters(lettersForYellowTile));
+        tiles.addGrayTile(new Letters(lettersForGrayTile));
     }
 
     private void processNoneMatchLetters(Letters answerLetters, Letters inputLetters, Tiles tiles) {