is the kind of move Spike likes to play. It's a double-purpose move (attack the black stone and spoil his chances of territory on the upper side), but it's too greedy.

Black has an excellent reply at . It splits the White stones apart and gets ready to attack at A or B. White can't deal with both threats. He's in trouble already!

• Strengthen your own stones before attacking or invading.
• Don't make two weak groups at the same time!