WPC 2017/Round 22

The namesake of this round is DWBH by Matej Uher (Slovakia), held on October 2013.[1]

Duration: 40 minutes. Total point value: 1600 points. Round winner: USA-A (Palmer Mebane, Walker Anderson, Thomas Snyder, Will Blatt), 1335 points.


The concept and planning of this round was done by Amit Sowani.

Round note: This is a team round containing 7 puzzles, across 7 puzzle types, all given on A4 sheets. In this round, participants cannot use pens, pencils or any other stationery. All puzzles have some cells covered by scratch labels. These labels can be scratched off a cell to reveal its contents.

In each puzzle, some specific cells must all be revealed while none of the remaining cells must be revealed. The specific cells to be scratched for each puzzle are indicated in the table below. To discourage guessing, even if one cell that isn't supposed to be revealed is scratched off, a smiley face will be visible, and a zero score will be awarded for the puzzle.

The team can work on only one puzzle at one instance and it is allowed to switch puzzles during the round. It is possible to scratch off the labels even using fingernails but the organizers highly recommend the use of coins which will be provided before the round commences.

An extra sheet will be provided. This sheet will contain the Battleship Fleet, the Pentomino Set, some other pictorial depictions of allowed/not allowed cells for puzzles, and a 2x2 grid containing 4 scratch labels so teams may try it out before starting the round.

This is a list showing cells to be revealed for each puzzle. The second column shows cells that must be revealed and the third column shows the cells that must not be revealed in order to receive credit for that puzzle.

Puzzle Must be revealed Must not be revealed
Minesweeper All non-mine cells Any cell containing a mine
Dotted Wall All cells containing the wall Any cells not containing the wall
Cave All cells inside the Cave Any cell outside the cave
Nanro All cells containing digits Any cells not containing digits
Battleships All cells containing ship segments Any cell not containing ship segments
Summon All cells containing digits Any cell not containing digits
Pentomino All cells containing Pentominos Any cell not containing Pentominos

Puzzles used were:

  1. Minesweeper by Prasanna Seshadri, 155 points
  2. Dotted Wall by Swaroop Guggilam, 260 points
  3. Cave by Prasanna Seshadri, 190 points
  4. Nanro by Prasanna Seshadri, 180 points
  5. Battleships by Amit Sowani, 210 points
  6. Summon by Rajesh Kumar, 265 points
  7. Pentomino (Pentominoes) by Prasanna Seshadri, 340 points