Some solving techniques of Sudoku Explainer that are not in other solvers. Unique Loop - a BUG-lite consisting of two digits that is bigger than Unique Rectangle. Rated from 4.6 to 5.1. BUG type 2 - if all extra candidates of BUG are for the same digit, then all candidates for this digit can be eliminated from cells that see all extra candidates. Rated 5.7. BUG type 3 - if all extra candidates share a house and form a Naked Subset with cells without the extra candidates, then all other candidates for those digits can be eliminated from that house. Rated from 5.8 to 6.1. BUG type 4 - if in both of cells containing extra candidates there are candidates for single digit (say digit X), then all candidates other than extra candidates and candidates for digit X can be eliminated. Rated 5.7. Bidirectional X-Cycle - a Continuous Nice Loop consisting of only single value. Rated 6.5. Forcing X-Chain - X-Chain (only Nice Loop variant). Rated from 6.6 to 6.9. Bidirectional Y-Cycle - a Continuous Nice Loop that goes only through bivalue cells. Rated from 6.6 to 6.9. Bidirectional Cycle - a Continuous Nice Loop that is not a Bidirectional X-Cycle nor Bidirectional Y-Cycle. Rated from 7.0 to 7.4. Forcing Chain - Alternating Inference Chain (only Nice Loop variant). Rated from 7.1 to 7.4. Aligned Triplet Exclusion - like Aligned Pair Exclusion (which is not listed there because it is used in Andrew's solver), but eliminates candidates from three digits, instead of two. Rated 7.5. Nishio Forcing Chain - a contradiction chain that uses only single value (Andrew's Nishio Forcing Chains use multiple values, so they aren't true Nishio Forcing Chains). Rated from 7.6 to 8.1. Multiple Forcing Chain - Cell and Unit Forcing Chains. More details in the Andrew's site. Rated from 8.2 to 8.7. Dynamic Forcing Chain - a Forcing Chain (Contradiction, Multiple or Double) that uses dynamicness, like Grouped nodes. It is like Hodoku's Forcing Net. Rated from 8.8 to 9.4. Nested Forcing Chain level 1 - a Dynamic Forcing Chain that uses Intersection Removal, Naked and Hidden Tuples, and Basic Fish nodes. Rated from 9.5 to 10.0. Nested Forcing Chain level 2 - Same as level 1, but also uses Forcing X-Chain, Forcing Chain, Bidirectional X-Cycle, Bidirectional Y-Cycle and Bidirectional Cycle nodes. Rated from 10.1 to 10.7. Nested Forcing Chain level 3 - Same as level 2, but also uses Cell Forcing Chain and Unit Forcing Chain nodes. Rated from 10.8 to 11.4. Nested Forcing Chain level 4 - Same as level 3, but also uses Dynamic Forcing Chain nodes. Hardest technique seen by SE ever. Rated from 11.5 to 12.0?. Nested Forcing Chain level 5 - Same as level 4, but also uses Nested Forcing Chain level 1 nodes. Still not seen by SE. Rated from 12.1? to ??.?.