In Puzzle 18, you should play BURNS i4 to block the primary bingo lane. Although you won’t be able to block any quadrants, the only bingo line at this time is column i, and as the board expands rightward, you will be able to close off the upper and lower right quadrants eventually. BURNS limits the board severely next turn and forces your opponent to consider how they will open the board in the future, as their primary open-board dynamic is now gone.