diff --git a/src/main/java/puzzle/SwedishGenerator.java b/src/main/java/puzzle/SwedishGenerator.java
index 03ab7c4..d8628df 100644
--- a/src/main/java/puzzle/SwedishGenerator.java
+++ b/src/main/java/puzzle/SwedishGenerator.java
@@ -540,17 +540,16 @@ public record SwedishGenerator(int[] buff) {
       return penalty;
    }
    
-   // ---------------- Mask generation ----------------
-   Grid randomMask2(Rng rng) {
-      var g = makeEmptyGrid();
-      
-      int placed = 0, guard = 0;
+   Grid randomMask(Rng rng) {
+      var g           = makeEmptyGrid();
+      int placed      = 0, guard = 0;
       
       while (placed < TARGET_CLUES && guard++ < 4000) {
-         var idx = rng.randint(0, SIZE - 1);
+         var idx = Grid.offset(rng.randint(0, R - 1),
+                               rng.randint(0, C - 1));
          if (g.isDigitAt(idx)) continue;
-         
          var d = OFFSETS[rng.randbyte(1, 4)];
+         
          g.setByteAt(idx, d.dbyte);
          if (!hasRoomForClue(g, idx, d)) {
             g.clear(idx);
@@ -560,27 +559,7 @@ public record SwedishGenerator(int[] buff) {
       }
       return g;
    }
-   Grid randomMask(Rng rng) {
-      var g           = makeEmptyGrid();
-      var targetClues = (int) Math.round(SIZE * 0.25);
-      int placed      = 0, guard = 0;
-      
-      while (placed < targetClues && guard++ < 4000) {
-         var r = rng.randint(0, R - 1);
-         var c = rng.randint(0, C - 1);
-         if (g.isDigitAt(r, c)) continue;
-         
-         var d = (char) ('0' + rng.randint(1, c == 0 ? CLUE_SIZE : 4));
-         g.setCharAt(r, c, d);
-         if (!hasRoomForClue(g, r, c, d)) {
-            g.setCharAt(r, c, C_DASH);
-            continue;
-         }
-         placed++;
-      }
-      return g;
-   }
-   Grid mutate2(Rng rng, Grid grid) {
+   Grid mutate(Rng rng, Grid grid) {
       var g  = grid.deepCopyGrid();
       var cx = rng.randint(0, R - 1);
       var cy = rng.randint(0, C - 1);
@@ -600,26 +579,6 @@ public record SwedishGenerator(int[] buff) {
       }
       return g;
    }
-   Grid mutate(Rng rng, Grid grid) {
-      var g  = grid.deepCopyGrid();
-      var cx = rng.randint(0, R - 1);
-      var cy = rng.randint(0, C - 1);
-      
-      var steps = 4;
-      for (var k = 0; k < steps; k++) {
-         var rr = clamp(cx + (rng.randint(-2, 2) + rng.randint(-2, 2)), 0, R - 1);
-         var cc = clamp(cy + (rng.randint(-2, 2) + rng.randint(-2, 2)), 0, C - 1);
-         
-         if (g.isDigitAt(rr, cc)) {
-            g.setCharAt(rr, cc, C_DASH);
-         } else {
-            var d = (char) ('0' + rng.randint(1, cc == 0 ? CLUE_SIZE : 4));
-            g.setCharAt(rr, cc, d);
-            if (!hasRoomForClue(g, rr, cc, d)) g.setCharAt(rr, cc, C_DASH);
-         }
-      }
-      return g;
-   }
    Grid crossover(Rng rng, Grid a, Grid b) {
       var out   = makeEmptyGrid();
       var theta = rng.nextFloat() * Math.PI;