by **Leren** » Sun Aug 11, 2019 4:07 am

Perhaps I can explain why this puzzle started so easily for me. It's due to my Str8ts background, where Compartment Interactions in the same row or column and the resulting HI/LO decisions are Bread and Butter moves.

The clue 8 in r1c9 was a dead giveaway. Given a 7/2 compartment split in Row 1 => r1c10 can then only be 8 and r2c10 must also then be 8. Next in Column 10 the lower compartment must be in the range 1-7, and given the 8/1 compartment split in Row 7, r7c10 can only be 1 or 9, and since it can't be 9 it must be 1. Next, in Column 3 the upper compartment can only be 1-3 or 7-9, but the range of the first compartment in Row 1 is 1-7 so r3c123 must be 123. In Column 5 given a 7/2 compartment split and 8 in the upper compartment, it's range can only be 3-9 and r89c5 must therefore be 12. Then given the 7/2 compartment split in Row 10 the larger compartment range must be 1-7 and r10c12 must be 98 and since there is a clue 8 in r7c1, r10c1 = 9 and r10c2 = 8. In Row 4 the 8/1 compartment split => r4c1 = 19, but r10c1 = 9 so r4c1 = 1. In Row 6 the LH compartment can only be 123 or 789, but since the upper compartment in Column 2 is already 123, it can only be 789, and given the values in r7c1 and r10c12 => r6c1 = 7, r6c2 = 9 and r6c3 = 8.

So you can see that I've been able to solve 9 cells at the start without even writing down any candidates. Now what I said above might sound quite complicated, but when you've done it many times you can do it almost without thinking.

In your solver, you can deal with these compartment split/clue arrangements on a case by case basis, to simulate what an experienced human solver would do, and reduce your need for guessing.

Leren