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The highest score possible is 40. This is because if you get 3 in a line (either horizontal, vertical or diagonal) you score three points and if you add another another spot on the end of that line get get another point and so on. To get a high score you must have the spots close together. One solution having a block of 3x4 with a extra spot on the edge (the position of the extra spot may result in you getting 37 points instead of 40). Another solution would be having three rows together, the first row with all five spots clicked, the second with only the middle three and the third row with all five spots clicked on again.