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Lost Entry - Recognizing Potential Break-thru's - March 23rd

 
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jabejochke



Joined: 16 Mar 2006
Posts: 21
Location: Reading

PostPosted: Sat Mar 25, 2006 9:30 pm    Post subject: Lost Entry - Recognizing Potential Break-thru's - March 23rd Reply with quote

Cannot find note submitted this morning -- certainly could have been my entry.

In working the puzzle of the 23rd, I encountered a not untypical experience for me. Had break-thru at Block 7 (left side, bottom) and solved from that point. However, I had gone to Candidate Profiling; processed all 9 Rows, 9 Columns and first 6 Blocks before hitting the break-thru at Block 7. The situation at that point is shown below (I hope).

Could I have recognized the potential break-thru at Block 7 (hence, gone there earlier or used different R/C/B sequencing)? Appreciate any tips or references to recognizing typical break-thru opportunities.

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David Bryant



Joined: 29 Jul 2005
Posts: 559
Location: Denver, Colorado

PostPosted: Sun Mar 26, 2006 12:56 am    Post subject: My answer got lost, too. Reply with quote

It wasn't your posting, jabejochke. I wrote a reply to your post this morning, and now that's gone, too. It's probably the "instability" samgj was talking about recently -- I think he's moving the web site to a new service provider, so the forum probably got backed up before you made your post, and then restored a bit later, if that makes any sense.

Anyway, the "break through" you're talking about is no doubt the hidden pair {1, 9} lying in r7c1 & r8c3. You can see this in the puzzle at the stage you described this morning by looking at column 2, and at row 9. You'll see the values {1, 9} lying in that column and in that row, and if you notice how they intersect in the bottom left 3x3 box you'll instantly recognize the "hidden pair."

The "trick" is to think in terms of pairs of values and not just in terms of single values. This particular puzzle feature (hidden pairs) is pretty common in samgj's puzzles, and you can almost always recognize them by seeing the pair of values lying _outside_ the box in which the "hidden pair" occurs. dcb
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PostPosted: Sun Mar 26, 2006 2:08 pm    Post subject: Reply with quote

David,

I do see the pair - and the source. Recognizing the source (the 1,9 in column 2 and the 1,9 in row 9) could have been the trigger to work Block 7 earlier than I did.

Thanks for the insight. It also looks like the same source coupled with the 7's in rows 8 and 9 show a triple in Block 7.

jabejochke
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samgj
Site Admin


Joined: 17 Jul 2005
Posts: 106
Location: Cambridge

PostPosted: Sun Mar 26, 2006 9:36 pm    Post subject: Re: My answer got lost, too. Reply with quote

David Bryant wrote:
It wasn't your posting, jabejochke. I wrote a reply to your post this morning, and now that's gone, too. It's probably the "instability" samgj was talking about recently -- I think he's moving the web site to a new service provider, so the forum probably got backed up before you made your post, and then restored a bit later, if that makes any sense.


Yeah -- apologies for this. The site has indeed moved. Your lost post was probably submitted after the new site appeared, but before your ISP had noticed and updated it's DNS. If you see this then you're on the new site, and there should be no more missing posts.

Sam
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