Hi. I found that ROSSINI and TENNISDOKU were not able to be solved, because in ROSSINI double arrows were not visible and in TENNISDOKU only few scores were visible (in application and in the pdf). Why??? How could be solved by the winners?

Hi,

In both cases you need to be very careful about the sentence beginning like this : "If there is no..."

To be clear : on rossini sudoku, there are no arrows because, on this particular puzzle, digits are never in strictly ascending or descending order. This is a very useful information.
On tennisdoku, where there isn't a tennis ball the score can't be one of a tennis match. For example, if there is no ball touching a "4", there can't be a "6" in the adjacent cells.

Does it help you ?

A few more help, if needed :

! SPOILER !


Let's have a look at Rossini sudoku :



Now look at Tennisdoku :

Thanks Ours brun.

lucarabino: Yes. In Tennisdoku (as also in Kid sudoku), all scores were not given as clues, as then it would have become too easy. But the grid was solvable with the given clues as the tennis balls provided enough hints. And 59 solvers did solve it.

Solution Booklet here

Thanks for having modified my post, I didn't know that there was a "spoiler tag".