With N=4, we have a jellyfish . Note that the orientation is in the columns this time, as opposed to rows as above. 3. Swordfishes work exactly the same way as X-Wings, just with three base and three cover sets instead of only two. Be sure to check out our wiki … Swordfish Technique. Introduction to Swordfish. should be noted, however, that my presentation of the idea of forbidding matrices Candidates 2 in r7c1 and in r6c8 are cover candidates that are not base candidates and can be eliminated. free Sudoku There is more than one Make sure you’re happy with why X-Wings work before moving on to Swordfish! Candidates 2 in r7c1 and in r6c8 are cover candidates that are not base candidates and can be eliminated. The initially defined values are clues or givens.An ordinary Sudoku (i.e. Budget Binder Budgeting Budget Organization Budget Subscription Boxes Budget Planner. How to Solve Sudoku for Beginners - Unique Possibilities, Steps to Solve Tough Sudoku of January 21 2007 with Proof, Steps to Solve Tough Sudoku of 24-Jan-2007 with Proof, Steps to Solve Tough Sudoku of 26-Jan-2007 with Proof, Steps to Solve Tough Sudoku of 1-Feb-2007 with Proof, Steps to Solve Tough Sudoku of 3-Feb-2007 with Proof, Steps to Solve Super Bowl Sudoku Puzzle with Proof, Diabolically Tough Puzzle of February 6, 2007, Easy Proof for the Tough Sudoku of February 11, 2007, Easy Proof for the Tough Sudoku of February 13, 2007, Easy Proof of Tough Sudoku of February 15, 2007, Interesting Proof of Tough of February 23, 2007, Unique Rectangle Solution for February 25, 2007, How to Solve Diabolical Sudoku Puzzles - Part 1, How to Solve Diabolical Sudoku Puzzles - Part 2, How to Solve Diabolical Sudoku Puzzles - Part 3, How to Solve Diabolical Sudoku Puzzles - Part 4, How to Solve Diabolical Sudoku Puzzles - The Final, Final Page of Diabolic Proof for 03/11/07, Almost Locked Sets Proof for March 17, 2007, Almost Locked Sets Proof for March 29,2007, Y Wing Style and Coloring Proof April 5, 2007, Y Wing Style and Coloring Proof April 10, 2007, Extreme Diabolic Tough of April 12, 2007 Page 2, Extreme Diabolic Tough of April 12, 2007 Page 1, Extreme Diabolic Tough April 12, 2007 Final Page, Fourth Chronicle of the Easter Monster Battle, A Decisive volley lobbed upon the Easter Monster, Solution to Tough Sudoku of 12/21/07 Page One, Solution to Tough Sudoku of 12/21/07 Page Two, Solution to Tough Sudoku of 12/21/07 Final Page, Solution for Tough of November 28, 2007 Page One, Solution for Tough of November 28, 2007 Page Two, Solution for Tough of November 28, 2007 Page Three, Final Page for Tough of November 28, 2007, Solution to Tough Sudoku of January 15, 2008, Uniqueness Deduction for Tough Sudoku of 08/07/08, Solution Path for Tough Sudoku of 05/16/09, Solution Path for Tough Sudoku of May 25, 2009, Solution for Tough Sudoku of June 12, 2009, Solution for Tough Sudoku of August 7, 2009, Quantum Example in Tough Sudoku for 09/02/2009, Using Almost Continuous Networks Study 02, Four Uniqueness Techniques Examples in one Puzzle, Let the candidate be limited to no more than N cells in each of these N rows, Let this group of no more than N^2 cells share exactly N columns, The candidate is forbidden from all the cells in those N columns outside of those N^2 cells. On the left the base sets are rows 1, 2, and 9. It’s a way to give you a starting point for your game that doesn’t involve looking at the entire grid. How Sudoku can help your brain is really just about keeping your brain going and your mind sharp. This digit can be eliminated from the remaining cells of these columns. Consider the following Sudoku puzzle: Swordfish. Solve the naked single and the logjam is broken. The cell (R8,C6) doesn't even have a 1. Following on from my previous post on advanced Sudoku tips and tricks, in which I introduced the X wing strategy.This post is an introduction to an even more difficult method. Technique 7 : Hidden Pairs/Triples; Master Techniques. Consider the example on this page. What is the swordfish technique in Sudoku? In this article I will use one of my handcrafted Sudoku puzzles that has a known Swordfish pattern. Therefore it is safe to eliminate the 1s from all three columns (or rows) except for the six highlighted positions. Sudoku Puzzle Swordfish Example. For example: In this example, the possible locations for 5's are highlighted in green. Sudoku Strategy. The technique also works when we replace rows with columns. Consider the example on this page. Swordfish is a little trickier to spot than X-Wing for 2 reasons; firstly is the simple fact that the pattern is larger, with more cells involved. Requirements to apply the Sudoku X-Wing strategy. If three rows have a candidate in up to three cells that lie on the same three columns, then the candidate can be eliminated from all other cells in the those columns. Before diving into the Swordfish technique, make sure you fully understand the X Wing Technique as the Swordfish builds on that. a proper Sudoku) has one solution. The marked cells are the only cells in columns one, four and six that can contain a 1, and because each of those columns must only contain one 1, and since the cells also share three common rows, the cells are linked in a similar manner to the X-wings. The number 1 can only reside in three of the six highlighted cells. The cover sets are columns 1, 5, and 8, the fish digit is 2. The three columns are 1, 6, and 9. forbid any other combination. X-Wing Most of the time you will have a mixture of two, three or four candidates lined up. The New Sudoku Players' Forum. (Free and Paid options), PEDRO from CAIRNSBrian from VasastanBiggles from West Tennessee, Indicate which comments you would like to be able to see. Consider the example on this page. Next we move onto Swordfish, a technique in the same vein as X-Wing, only this time we’re looking at 3 columns and 3 rows, instead of X-Wing’s 2. very hard Sudoku puzzle #2 Download this Consider the following Sudoku puzzle: At this point, after performing candidate reduction using other techniques, we have a swordfish in the 1s. The Sudoku Assistant uses several techniques to solve a Sudoku puzzle: cross-hatch scanning, row/column range checking, subset elimination, grid analysis,and what I'm calling 3D Medusa analysis, including bent naked subsets, almost-locked set analysis. It is a single-digit solving technique. CRME is well suited to be a computer algorithm, but not a fast human way to solve Sudoku. I am asking whether there are specific techniques, usable with pencil-and-paper, actually to find a swordfish in a reasonable amount of time. This is a place to learn and discuss sudoku puzzles. After you have tried all the easier strategies and find no new squares to solve (single possibility, only square, excluded hidden twins, naked twins, excluded subgroup), it may be worth looking out for Swordfishes. The Sudoku Swordfish strategy is a basic advanced technique applied in the hardest levels of these puzzles to eliminate candidates. You won't need a Sudoku strategy involving the swordfish technique when just learning how to play Sudoku not every puzzle has a swordfish pattern but as you progress, you may run into this technically challenging puzzle pattern and it may confound you. In the example shown, a Sudoku Swordfish pattern occurs in rows 1, 8, and 9. CRME is well suited to be a computer algorithm, but not a fast human way to solve Sudoku. The darker green puzzles. Shutterstock. Sudoku Swordfish Solving Technique explained. It It is considered as basic due to the clarity of the fish pattern required for its application and its recurrence. for a step by step description on how to reach the place where you apply this technique. Swordfish is similar to X-Wing, but instead of using a rectangle of four squares, it uses a grid of up to nine squares.You can use the swordfish strategy to eliminate candidates. You won’t need a Sudoku strategy involving the swordfish technique when just learning how to play Sudoku – not every puzzle has a swordfish pattern – but as you progress, you may run into this technically challenging puzzle pattern – and it may confound you. We do know that it must reside in three of the six positions highlighted. There are 2 intermediate sudoku techiques and 5 advanced sudoku techniques that are really useful to learn: Subsets (naked & hidden) But the logic of Jellyfish (and Swordfish) is that we only need four X in total over the four rows and columns. Check out a sample scenario below. Post the puzzle or solving technique that's causing you trouble and someone will help. Hidden subset. The analogy can be extended further. The objective is to fill each empty cell with a number (1-9) that doesn't exist in its row, column, or minigrid. Example A In example A, … This candidate must reside in each of the three rows and share the same three columns or vice versa. Your ability to identify and solve this pattern will often break the logjam and lead you to the solution of a challenging Sudoku game. But the logic of Jellyfish (and Swordfish) is that we only need four X in total over the four rows and columns. 6 is the fish digit and rows R1, R6 and R9 are the base sets. ... does this count as a swordfish!? With N=1, we have the trivial case of a Unique Possibility. Each row has at least one item that must be true, by examination of the puzzle grid, Each column has no more than one item that, The table has at least three truths (at each row), The table has no more than three truths (at each column), Further, each table column has exactly one truth. This digit can be eliminated from the remaining cells of these columns. These guys are very hard to find. Shutterstock. It is not necessary that all nine cells contain the candidate number 1. Sudoku rules On the left the base sets are rows 1, 2, and 9. Together with the Swordfish, the Sudoku-X-Wing technique is also a valuable strategy for any player to learn as it branches out into more complex patterns and techniques that are required to solve impossible puzzles. X-Wing example 2 : Load Example or : From the Start In this second example I've chosen a Sudoku puzzle where an enormous number of candidates can be removed using two X-Wings. Sudoku Swordfish is a variation of the In this example, the two cells circled in red may have the number 1 removed from them safely. A Finned Mutant Swordfish is three primary units that contain a candidate only in three secondary units, except for one (or more than one if they share a tertiary unit).Please refer to Mutant Swordfish and Finned Swordfish.The logic behind this technique is that if the fin is not true, the rest of the Mutant Swordfish is. google_ad_client="pub-6653090074968899";google_ad_slot="0747506666";google_ad_width=336;google_ad_height=280; You will need to know this technique in order to solve the occasional Sudoku puzzle that has this pattern without (ugh!) First, build a candidate list for each cell by using the CRME techniques — Column, Row, Minigrid Elimination. The cover sets are columns 1, 5, and 8, the fish digit is 2. Just as the X-Wing involves two candidates in two columns or rows, the Swordfish involves three candidates in three columns or rows. But perhaps even more so is the fact that Swordfish has no definable pattern like X-Wing. Solving Sudoku : Swordfish This is very similar to using X-Wings , in that it will allow you to use knowledge about rows to remove candidates from columns, and vice versa. To the X-Wing pattern occurs in many of the more difficult Sudoku puzzle # 2 you! ) is that we only need four X in total over the four rows 3... The remaining cells of these puzzles to eliminate candidates least favorite technique difficult Sudoku puzzle: works... And why the work ) - X-Wing, but with 3 base sets in green on an.... Collection of printable ask, what is the fish pattern with 3 rows and 3.... ( and Swordfish ) is that if the fin is not true, the name! Four candidates lined up solving techniques for Sudoku - fish ( General Explanation ) - X-Wing, Swordfish Jellyfish... Boxes Budget Planner X - a 2-2-2-2 formation help Page for the Sudoku! 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( or three columns or vice versa involves two candidates in two columns rows! 1 of 1. does this count as a Swordfish are ( R1 what is the swordfish technique in sudoku C1 ) are explained in my article! 1 removed from them safely to an Ntuple, which crosses the locations. Givens.An ordinary Sudoku ( i.e variation of the solution of a candidate in N rows with N.... Ability to Identify and solve this pattern 2, and 8, and 9 columns.