any Sudoku experts? trying to figure out if this "tutorial" is flawed

I know the general jist of Sudoku, but I’m trying to advance my knowledge of little tips and tricks and shit to look for, so that an Intermediate puzzle doesn’t take me 30 minutes to solve.

I stumbled into this tutorial here. I understand the logic only up until this point:

– I understand that the 6 in cell F9 means there can not be a 6 in cells F4, F5, or F6.
– I understand that the 6 in cell H4 means there can not be a 6 in cells D4 or E4 (or the above-mentioned F4).
– which leaves, in my mind, the possibility that the 6 could exist in cells D5, D6, or E6 - but the author claims that the 6 can only go in cell E6 - period, end of story.

Is there some “trick” that I’m missing that eliminates cells D5 and D6 as being a possibility for the 6, in that center 3x3 box?

Thanks -

The author is looking at row E, not the center box. There are only four open spots in Row E: E2, E4, E6, and E8. E6 is the only cell of the four that does not have a 6 in its column.

Look at just row “E”, there are four empty squares three of which cannot be 6 because they already have a 6 in the columns … ergo, E6 is the only possible place for the 6 in row “E”.

ok, NOW I get it - thanks for both explanations! I admit that I do need to get better at “thinking outside the box” on these things.

Sudoku is a wonderful game, and I’m glad you’re getting into it.

thanks, ekedolphin (I’m assuming your comment was sincere) - I’ve always had a knack for the “logic puzzles” (i.e. “the person seated to the left of the girl with the dress that wasn’t green took either the car or the trolley to the supermarket”) - and now I’m starting to see how applying that same sort of… well, logic… is necessary to filling these Sudoku things out.

Yeah, it’s really that same sort of logic puzzle, distilled down to its most succinct form.

If you live Sudoku, don’t pass up Nurikabe, a similar type of puzzle with completely different rules… and no counting!

My favorite is nonograms.

Yes, I’m quite sincere. I’ve been a fan of Sudoku for several years. I used to buy Sudoku puzzle books, but doing so would be kinda silly now that I’ve got a smartphone with a Sudoku app.

I play a game in the morning most of the time and a game at night. I usually hover around the 50th percentile. I use a method that is relaxing but not really fast. Great game.

So, what’s a good sudoku app for iPad?

I haven’t played Sudoku in ages - I really should start getting back into the gist of it

Anyhow, I don’t know if this has been answered or not (only just found the thread and I don’t log on that often), but he’s looking at row E only.

The 6 in F9 means that there can’t be a 6 in E8.
The 6 in H4 means that there can’t be a 6 in E4.
The 6 in G2 means that there can’t be a 6 in E2. The only vacant square left is E6.

This then helps locate the 6 in the next 3x3 box, because F1, F2 and F3 can’t be 6 (because of the 6 in F9) and E2 can’t be 6 because we have just found a 6 in the E row. This leaves the 6 to be in D3.

I do. I know if it’s been answered or not. Do you want to know how I know?

I like Killer Sudoku!