Stuck on puzzle

List of contributions in 'Tuff One!'

Tuff One! contributed by Digitaldood

Even though there are 2 singles in this puzzle, I have solved 6 more cells and am at a sticking point. This is a tuff one!! What strategies can be applied?

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Submit661 (re: Tuff One!) contributed by John Wood

Looks like this is the start state of the puzzle rather than when you got stuck.

Anyway, here\'s the first few squares I managed to solve

Ch has to be a 3 as there is no other choice for the square.

Gc has to be a 7 - also only choice

More tricky one - Ac must be a 3 - there are only two squares in row A it can go Aa and Ac but it can\'t go in Aa because of the twin 1,4 in squares Aa and Ab (only squares that 1,4 can go).

This knocks out a possibility of 3 in Gc and this must now be an 8.

Also in this region Ha must be a 3 as that is the only square that can take it.

Now in Row H a 7 can go in Ig or Ii, But actually Ii is not possible as 6 and 9 must go in either Hi or Ii so it can\'t be a 7 here.

That knocks out a 7 in Cg so that must now be a 2. Looking in the region Ag the square Bi must now be a 7.

Does that help at all?

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