Common mistakes

Ladder escaping too early

Red to move. In this situation Red has a win with perfect play. He only has to find a good ladder escape from the ladder starting at h1, g2. c2 is such an escape. However, playing c2 in this stage of the game is a losing move because Blue can play any of f1, f2, e2. Another good escape from the second line would be c3, but once again it fails it this situation. So what should Red do? The only way to win is to play out the ladder to e2 and then jump to c2:

Now Blue cannot block Red's connection. A further development game could be: d2, c3, d3, b5 and Red makes a double bridge, connecting c3 and c6.

Bad bridge intrusion

The same situation can be lost if Red intrudes into the d4-f3 bridge at e3. Of course if Blue doesn't see the trap he will fill up the bridge at e4 and then Red's e3 is a ladder escape. But Blue can play f2 and win because the ladder moved from second to the third line, and Red has no ladder escape from the third line. Remember that such a bridge intrusion removes the ladder one line further from the edge, which is often a disadvantage to the attacking player.