Disappearing nine patch

The disappearing nine patch has become something of a phenomenon.  The concept is easy. You take nine squares and sew them together to make a nine patch (3x3 block).  Then you take a ruler and rotary cutter and cut the sewn block in half horizontally and vertically to make more pieces.  These are then flipped and rotated and sewn back together to form a new block.  The pattern depends on the number of the pieces, the new orientation of the pieces and of course if any additional sashing is used.

This is one pattern from patchwork square which cuts the nine patch into four,  you can see it here 

Jordan Fabrics offer a free pattern to go with this video - again the nine patch is cut into four.

This is another orientation from Crazy Daves Crew - again nine patch is cut into four but this time the large squares created are grouped to the centre

Missouri Star Quilt Company used sashing to ramp up the pattern using the nine patches cut into four agsin.

Missouri Star again but snowballing some of the corners before cutting into four.

Another disappearing nine patch but using a different cutting pattern.  Instead of four equal pieces they are cutting and swapping the outside edges with a second block - this is sometimes called the double disappearing nine patch to distinguish it from the method where the block is cut into four. 

Teresa Downunder gives four different takes on the block here.