In the thread of Tarak about "Revision of SE ratings and resolution rules" a new rating system is born for single Sudoku's and Sakaku's.

I would like to suggest a method for SE rating for overlapping Sudoku's, like Twins, Samurai, Kazaguruma etc.

Upwards compatible with the new SE rating for singles, and based on the Pythagoras length in n-dimensions.

So it leads always to a rating (slightly) higher then the maximum of each individual SE.

A Twin consists of 2 Sudoku's, each with a SE rating, say 3.0 en 4.0 eg.

The SE rating of the Twin is based on sqrt(sqr(3.0)+sqr(4.0))=5.0 but that is too high (says my feeling).

So make it a bit more difficult... The SE ratings starts at 1.0 and not 0.0 . Subtract 1.0 from the SE values and add 1.0 at the end.

Now the SE rating for a Twin is sqrt(sqr(3.0-1.0)+sqr(4.0-1.0)) + 1.0 = 4.61

Better but still too high... Especially when considering a Samurai with 5 Sudoku's.

Eg let each Sudoku have 3.0 rating then the Samurai ends up with a rating sqrt(5 * sqr(3.0-1.0))+1.0 = 5.47. That's almost double.

One step further : divide the sum of sqr's with sqrt(n), where n is the number of Sudoku's (Pythagoras dimensions).

That leads to sqrt(5 * sqr(3.0-1.0)/sqrt(5))+1.0= 3.99 . Acceptable?

In general the formula would be:

SE puzzle = sqrt([sum of sqr(each single SE - 1.0)]/sqrt(n))+1.0, where n is the number of Sudoku's in the puzzle

Is this something (or another can of worms)?