diff -r 8ae7a8464c52 -r ae4e3694c2d3 minesweeper/src/main/java/org/apidesign/demo/minesweeper/MinesModel.java
--- a/minesweeper/src/main/java/org/apidesign/demo/minesweeper/MinesModel.java	Sun Mar 09 15:03:01 2014 +0100
+++ b/minesweeper/src/main/java/org/apidesign/demo/minesweeper/MinesModel.java	Sun Mar 09 15:21:42 2014 +0100
@@ -245,6 +245,7 @@
                 } else {
                     TOUCH.play();
                     expandKnown(model, data);
+                    model.computeMines();
                 }
             break;
         }
@@ -272,9 +273,18 @@
         }
         final Square sq = columns.get(x);
         if (sq.getState() == SquareType.UNKNOWN) {
-            sq.setState(SquareType.N_0);
-            model.computeMines();
-            if (sq.getState() == SquareType.N_0) {
+            int around = 
+                minesAt(model, x - 1, y - 1) +
+                minesAt(model, x - 1, y) +
+                minesAt(model, x - 1, y + 1) +
+                minesAt(model, x , y - 1) +
+                minesAt(model, x, y + 1) +
+                minesAt(model, x + 1, y - 1) +
+                minesAt(model, x + 1, y) +
+                minesAt(model, x + 1, y + 1);
+            final SquareType t = SquareType.valueOf("N_" + around);
+            sq.setState(t);
+            if (t == SquareType.N_0) {
                 expandKnown(model, x - 1, y - 1);
                 expandKnown(model, x - 1, y);
                 expandKnown(model, x - 1, y + 1);
@@ -286,4 +296,17 @@
             }
         }
     }
+    
+    private static int minesAt(Mines model, int x, int y) {
+        if (y < 0 || y >= model.getRows().size()) {
+            return 0;
+        }
+        final List<Square> columns = model.getRows().get(y).getColumns();
+        if (x < 0 || x >= columns.size()) {
+            return 0;
+        }
+        Square sq = columns.get(x);
+        return sq.isMine() ? 1 : 0;
+    }
+    
 }