A fresh Kakuro grid sits in front of you, every white cell empty. Your eye lands on a 27 running across five cells, so you start there. 9, 8, 6, 3, 1? 9, 7, 5, 4, 2? 8, 7, 6, 4, 2? All valid. There are eleven different digit sets that add to 27 in five cells, and nothing yet tells you which one is …