The first step here is the major intuitive leap of the puzzle: To realise the image is in fact the representation of a dart board. This can be inferred from the colour scheme, the number of columns, the markings, and the title Checking Out, which is itself darts jargon.
Now that we have identified what we're looking at, we can deduce that the X marks are the points at which a player's darts landed, and their order is further given by the attached boxes. This ordering is supported by the fact the first and last throws land in doubling segments. In all likelihood we want to insert letters in these boxes, but it's not clear how to do so yet since we don't know the player's actual score - the segment (or in this case, column) values have not been supplied for us.
Making the first column represent the segment numbered 1 doesn't seem to give us anything useful, so there must be a better way to work out the numbering. This is in fact again hinted at by the title: "Checking Out" means to complete a game of darts by scoring exactly a fixed amount, commonly 301 or 501. There are too few throws in this diagram for the score to reach 501, so with the assumption the final score is 301, one can quickly determine the correct labelling, which is as follows:
Finally we want to use this information to insert letters into the boxes. It turns out the required method is to insert the alphanumeric equivalent of the segment number each dart has landed in. There is one exception here: one of the darts lands in the outer bullseye and on the edge of two segments, implying it instead stands for the usual outer bullseye score, 25 (so the letter Y).
Putting this all together gives the message PHIL TAYLOR AKA, which is a clue asking for the nickname of famed darts player Phil Taylor, also known as "The Power".
|The answer is: thepower|