Solution/discussion of is.gd/4_days_left_2022_str8t
Posted: Wednesday 21. December 2022, 15:36
This is an interesting one!
After standard elimination, we are left with numerous undecided, interacting hi/lo's and, to me, no obvious way forward. Ben (in the 'extreme' str8ts discussion of week 652) points out 2-fish 8 25 and C-H1 must contain 8 (UR A1), also CE A9!=3. Let me throw in H8!=9 (UR). All good stuff but not decisive.
What did work for me was CE to trim down compartment ranges. After a few unsuccessful tries, I hit pay dirt at F3=7: this implies G4=2 --> 3 required in G56 but G2=3. The problem is not so much F3, but the implied F4=5, which can be eliminated. Same thing for F4=4.
After working out the consequences, my winning move was F4!=3: it would not only imply G4=2 but also a near-UR on AF35: A5!=45. This does two things: NP 36 col 5 and A4=5 (gap), the latter implying J2=5, G2=34. G4-6 must be 123, in particular G5=3 in conflict with the NP 36. F4=2, the rest wasn't difficult.
After standard elimination, we are left with numerous undecided, interacting hi/lo's and, to me, no obvious way forward. Ben (in the 'extreme' str8ts discussion of week 652) points out 2-fish 8 25 and C-H1 must contain 8 (UR A1), also CE A9!=3. Let me throw in H8!=9 (UR). All good stuff but not decisive.
What did work for me was CE to trim down compartment ranges. After a few unsuccessful tries, I hit pay dirt at F3=7: this implies G4=2 --> 3 required in G56 but G2=3. The problem is not so much F3, but the implied F4=5, which can be eliminated. Same thing for F4=4.
After working out the consequences, my winning move was F4!=3: it would not only imply G4=2 but also a near-UR on AF35: A5!=45. This does two things: NP 36 col 5 and A4=5 (gap), the latter implying J2=5, G2=34. G4-6 must be 123, in particular G5=3 in conflict with the NP 36. F4=2, the rest wasn't difficult.