diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
index 7aca04a..47ec3a8 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/NewLevelManager.java
@@ -40,7 +40,8 @@ public class NewLevelManager {
     public static int PRE_SAVES_MIN = 3;
     public static int PRE_SAVES_MAX = 10;
 
-    private final double CHALLENGE_GENERATION_PROBABILITY = 0.9;
+    private final double CHALLENGE_GENERATION_PROBABILITY = 0.25;
+    private final int CHALLENGE_ITERATIONS = 4;
 
 
     public static NewLevelManager getInstance(Context context, SharedPreferences settings) {
@@ -84,16 +85,8 @@ public class NewLevelManager {
     public int[] loadDailySudoku() {
         DateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
         String toHash = "Sudoku/.PrivacyFriendly/." + dateFormat.format(new Date());
-        boolean generateChallenge = new Random(toHash.hashCode()).nextDouble() >= CHALLENGE_GENERATION_PROBABILITY;
         QQWingController controller = new QQWingController();
-        int[] result;
-
-        if (generateChallenge) {
-            result = controller.generateFromSeed(toHash.hashCode(), GameDifficulty.Challenge);
-        } else {
-            result = controller.generateFromSeed(toHash.hashCode(), GameDifficulty.Unspecified);
-        }
-        return result;
+        return controller.generateFromSeed(toHash.hashCode(), CHALLENGE_GENERATION_PROBABILITY, CHALLENGE_ITERATIONS);
     }
 
     public int[] loadLevel(GameType type, GameDifficulty diff) {
diff --git a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
index eb78863..87a81b1 100644
--- a/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
+++ b/app/src/main/java/org/secuso/privacyfriendlysudoku/controller/QQWingController.java
@@ -4,6 +4,7 @@ import android.os.Parcelable;
 import android.util.Log;
 
 import java.util.LinkedList;
+import java.util.Random;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.Date;
@@ -53,20 +54,27 @@ public class QQWingController {
         return generated;
     }
 
-    public int[] generateFromSeed(int seed, GameDifficulty difficulty) {
+    public int[] generateFromSeed(int seed) {
+        return generateFromSeed(seed, 1, 1);
+    }
+
+    public int[] generateFromSeed(int seed, double challengePermission, int challengeIterations) {
         generated.clear();
         QQWing generator = new QQWing(GameType.Default_9x9, GameDifficulty.Unspecified);
-        boolean havePuzzle = false;
+        boolean continueSearch = true;
+        Random random = new Random(seed);
+        int seedFactor = 2;
 
-        while(!havePuzzle) {
-            seed++;
+        while(continueSearch && challengeIterations > 0) {
+            seed *= seedFactor;
             generator.setRandom(seed);
             generator.setRecordHistory(true);
             generator.generatePuzzle();
 
-            if (difficulty == GameDifficulty.Unspecified && generator.getDifficulty() != GameDifficulty.Challenge
-                    || difficulty == generator.getDifficulty()) {
-                havePuzzle = true;
+            if (generator.getDifficulty() != GameDifficulty.Challenge || random.nextDouble() < challengePermission) {
+                continueSearch = false;
+            } else {
+                challengeIterations--;
             }
         }
 
@@ -223,6 +231,10 @@ public class QQWingController {
         }
     }
 
+    public boolean isImpossible() {
+        return solveImpossible;
+    }
+
     private static class QQWingOptions {
         // defaults for options
         boolean needNow = false;