The first block is a one half fraction of the 23 plus 2 center points. Block 2 is the second half fraction of the factorial part with two center points. The third block consists of 6 star points, plus to center points. Each of the three blocks contains 2 center points and the first two blocks have half of the corner points each. The third block contains the star points and is of size 8.
Rollover the words 'Block 1', 'Block 2', and 'Block 3' in the graphic above. Do you see how they use center points strategically to tie the blocks together? They are represented in each block and they keep the design connected