Logic Masters Deutschland e.V.

Taking a stab at creating a Full Quad-Rank puzzle! This rule is created by aqjhs, and this puzzle uses nearly the same ruleset as Marty Sears' puzzle: Ranked Quads, but with a QuattroQuadri grid. I am guessing 3 stars for difficulty, but familiarity with the Full Quad-Rank constraint may bring the difficulty down. Enjoy!

Rules:

QuattroQuadri: Place the digits 1-9 once each in every 3x3 box such that numbers do not repeat in a row or column.

Kropki Dots: Digits separated by a white dot are consecutive. Digits separated by a black dot are in a 1:2 ratio. Not all dots are necessarily given.

Quadruples: Digits in circles must be present at least once in the cells the clue touches.

Full Quad-Rank: All the 2x2 areas of the grid, when read in western reading order, make a total of 25 four-digit numbers. If all these 4-digit numbers are ranked from lowest to highest (with rank 1 being the lowest and rank 25 being the highest), the number in a circle also gives the rank of its surrounding 2x2 area. All the 4-digit numbers are different, so there are no tied ranks.