Hi Tappers!  Here’s a quick tutorial on how to find the gem in the 6x6 excavation grid using a maximum of only 10 shovels.

Starting with the 6x6 grid oriented however you want it to go, we choose our squares 1, 2, and 3 to take out the most possible area in the interior of the grid.

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Squares 1, 2, and 3 can be chosen in any order.  If you find a rock under any of these three squares, just check the adjacent squares in any order, one of which must have the gem!

Now, let’s move on to squares 4, 5, 6, and 7.  These squares are chosen on the edges such that each square has three adjacent squares we haven’t eliminated yet.  Squares 4, 5, 6, and 7 can again be chosen in any order.

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Once again, if you find a rock under square 4, 5, 6, or 7 - just check the three adjacent squares around the rock to find the gem.

Now here is where the strategy becomes really important!  Look at the two blank squares left near the bottom left corner of the diagram.  If we first check the square between these two blank spaces as our 8th selection, then if it is a rock we can use our 9th and 10th selections to check the two blank squares and find the gem.

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If square 8 does not have a rock, then move on to the two blank squares at the bottom right corner of the diagram.  Choose one of the two as square 9, and if it is a rock you will find the gem under the other one on your 10th selection!

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If square 9 is not a rock, you’ve only got one square left - this is guaranteed to have the gem!

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