diff --git a/src/main/java/com/charego/freecellfx/model/Game.java b/src/main/java/com/charego/freecellfx/model/Game.java
index f5bea05..0e9ac32 100644
--- a/src/main/java/com/charego/freecellfx/model/Game.java
+++ b/src/main/java/com/charego/freecellfx/model/Game.java
@@ -1,16 +1,14 @@
 package com.charego.freecellfx.model;
 
-import com.charego.freecellfx.model.pile.Cell;
-import com.charego.freecellfx.model.pile.Pile;
-import com.charego.freecellfx.model.action.MoveAction;
-import com.charego.freecellfx.model.pile.Foundation;
-import com.charego.freecellfx.model.pile.Tableau;
-
 import java.util.ArrayList;
-import java.util.Deque;
-import java.util.LinkedList;
 import java.util.List;
 
+import com.charego.freecellfx.model.action.MoveAction;
+import com.charego.freecellfx.model.pile.Cell;
+import com.charego.freecellfx.model.pile.Foundation;
+import com.charego.freecellfx.model.pile.Pile;
+import com.charego.freecellfx.model.pile.Tableau;
+
 public class Game {
 	private List<Cell> cells = new ArrayList<>(4);
 	private List<Foundation> foundations = new ArrayList<>(4);
@@ -149,47 +147,4 @@ public class Game {
 		}
 	}
 
-	private static class MoveTracker {
-		private final Deque<MoveAction> nextMoves = new LinkedList<>();
-		private final Deque<MoveAction> previousMoves = new LinkedList<>();
-
-		public void clearMoves() {
-			nextMoves.clear();
-			previousMoves.clear();
-		}
-
-		public boolean hasLastMove() {
-			return !previousMoves.isEmpty();
-		}
-
-		public MoveAction getLastMove() {
-			MoveAction lastMove = previousMoves.pop();
-			nextMoves.push(lastMove);
-			return lastMove;
-		}
-
-		public boolean hasNextMove() {
-			return !nextMoves.isEmpty();
-		}
-
-		public MoveAction getNextMove() {
-			MoveAction nextMove = nextMoves.pop();
-			previousMoves.push(nextMove);
-			return nextMove;
-		}
-
-		public void addMove(MoveAction move) {
-			MoveAction nextMove = nextMoves.peek();
-			/*
-			 * if new move differs from saved next move, clear the remaining
-			 * next moves
-			 */
-			if (move.equals(nextMove)) {
-				nextMoves.pop();
-			} else {
-				nextMoves.clear();
-			}
-			previousMoves.push(move);
-		}
-	}
 }
diff --git a/src/main/java/com/charego/freecellfx/model/MoveTracker.java b/src/main/java/com/charego/freecellfx/model/MoveTracker.java
new file mode 100644
index 0000000..83a3fb3
--- /dev/null
+++ b/src/main/java/com/charego/freecellfx/model/MoveTracker.java
@@ -0,0 +1,56 @@
+package com.charego.freecellfx.model;
+
+import java.util.Deque;
+import java.util.LinkedList;
+
+import com.charego.freecellfx.model.action.MoveAction;
+
+/**
+ * Records moves to enable redo and undo actions.
+ */
+public class MoveTracker {
+
+	private final Deque<MoveAction> nextMoves = new LinkedList<>();
+	private final Deque<MoveAction> previousMoves = new LinkedList<>();
+
+	public void clearMoves() {
+		nextMoves.clear();
+		previousMoves.clear();
+	}
+
+	public boolean hasLastMove() {
+		return !previousMoves.isEmpty();
+	}
+
+	public MoveAction getLastMove() {
+		MoveAction lastMove = previousMoves.pop();
+		nextMoves.push(lastMove);
+		return lastMove;
+	}
+
+	public boolean hasNextMove() {
+		return !nextMoves.isEmpty();
+	}
+
+	public MoveAction getNextMove() {
+		MoveAction nextMove = nextMoves.pop();
+		previousMoves.push(nextMove);
+		return nextMove;
+	}
+
+	public void addMove(MoveAction move) {
+		MoveAction nextMove = nextMoves.peek();
+
+		/*
+		 * If there is a saved next move and it differs from the player's move,
+		 * clear the remaining next moves because the paths have diverged.
+		 */
+		if (move.equals(nextMove)) {
+			nextMoves.pop();
+		} else {
+			nextMoves.clear();
+		}
+		previousMoves.push(move);
+	}
+
+}