X wing. At this point we do not know which three cells the 1 will reside in. The first is a '2-Wing'. Congratulations on solving a very difficult Sudoku puzzle. These are obviously quite tricky to manage without using pencilmarks! To prove this technique, I prefer to use induction. with N=5, the creative name squirmbag is used. You will also need to solve some cells using the colors technique. The use of this strategy usually results in the unveiling of the solution of one or several cells. Make sure you’re happy with why X-Wings work before moving on to Swordfish! What is the swordfish technique in Sudoku? "Solve Sudoku" In the example shown, a Sudoku Swordfish pattern occurs in rows 1, 8, and 9. On the left the base sets are rows 1, 2, and 9. To prove this technique, I prefer to use induction. Swordfish Technique. 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. Just as the X-Wing involves two candidates in two columns or rows, the Swordfish involves three candidates in three columns or rows. Swordfish is a generalization of X-Wing. the puzzle) is a partially completed grid.A grid has 9 rows, 9 columns and 9 boxes, each having 9 cells (81 total). Swordfish in the Rows When all candidates for digit X in 3 rows are located in only 3 columns, we can eliminate all candidates for digit X from those 3 columns except those located on the defining 3 rows. Sudoku rules For example: In this example, the possible locations for 5's are highlighted in green. Check out a sample scenario below. WELCOME TO PUZZLES-ONLINE-NICHE These Sudoku solutions techniques are for the serious Sudoku … 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. The technique also works when we replace rows with columns. Consider the example on this page. AFFILIATE DISCLOSURE POLICY. X-Wing A Swordfish is a 3 by 3 nine-cell pattern where a candidate is found on three different rows (or three columns) and they line up in the opposite direction. It is not necessary that all nine cells contain the candidate number 1. Sudoku Techniques including X Wing and Swordfish. Therefore it is safe to eliminate the 1s from all three columns (or rows) except for the six highlighted positions. Terminology and grid layout. As a member you get heaps of benefits. Post the puzzle or solving technique that's causing you trouble and someone will help. Solving Techniques for sudoku - Fish (General Explanation) - X-Wing, Swordfish, Jellyfish Swordfish A Swordfish occurs when in three rows all possible cells for a given digit lie in three columns. 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. Swordfish in the Rows . In this example, the swordfish is missing 5's at c6,d4. type of such a matrix. CRME is well suited to be a computer algorithm, but not a fast human way to solve Sudoku. 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. Swordfish. 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. From today onwards, you will find the swordfish technique become a regular feature in the Times2 . 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 – … 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. Swordfish Swordfish is a more complicated version of X-Wing. Swordfish A Swordfish occurs when in three rows all possible cells for a given digit lie in three columns. Your ability to identify and solve this pattern will often break the logjam and lead you to the solution of a challenging Sudoku game. 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. These cells are highlighted in grey. With N=4, we have a jellyfish. a proper Sudoku) has one solution. This is similar to Naked subset, but it affects the cells holding the candidates. How to solve Sudoku. guessing. Take a look at the following Sudoku puzzle. They come in five levels of difficulty. With N=4, we have a jellyfish. Sudoku Swordfish Solving Technique explained. Some of these terms (except locked candidates and color) are explained in my illustrative article Horizontally adjacent rows are a band, and vertically adjacent columns are a stack. Joining is quick and free. The Sudoku Swordfish strategy is a basic advanced technique applied in the hardest levels of these puzzles to eliminate candidates. It is a single-digit solving technique. Note that the orientation is in the columns this time, as opposed to rows as above. A Finned Swordfish is a pattern that is one cell short of being a swordfish - in other words, three columns that contain a candidate in only three rows, except for one, and vice versa. The yellow high lighted cells show the X-Wing formation. Eventually we will fix three candidates somewhere in those cells which excludes all other candidates in those units. Consider the following Sudoku puzzle: The three columns are 1, 6, and 9. I understand what swordfish are and why the work. The objective is to fill each empty cell with a number (1-9) that doesn't exist in its row, column, or minigrid. This digit can be eliminated from the remaining cells of these columns. Read my article
Hidden subset. In the example,
Make sure you're happy with why X-Wings work before moving on to Swordfish! With N=1, we have the trivial case of a Unique Possibility. Sudoku has also been linked to declines in the potential for dementia to progress and has helped patients with mental health issues regain some normal daily function abilities. Using the ‘Swordfish’ Sudoku solving technique Step 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 . An Exhaustive Study on different Sudoku Solving Techniques Abstract ‘Sudoku’ is the Japanese abbreviation of a longer phrase, ‘Suuji wa dokushin ni kagiru’, meaning ‘the digits must remain single’. Candidates 2 in r7c1 and in r6c8 are cover candidates that are not base candidates and can be eliminated. I mean, what process do you use to look for swordfish in a diagram - … You will encounter naked and hidden singles, naked pairs, and locked candidates. A Sudoku (i.e. In row 9 the cells are (R9,C1), (R9,C6) and (R9,C9). In the example shown, a Sudoku Swordfish pattern occurs in rows 1, 8, and 9. The technique also works when we replace rows with columns. A Swordfish is a 3 by 3 nine-cell pattern where a candidate is found on three different rows (or three columns) and they line up in the opposite direction. for a step by step description on how to reach the place where you apply this technique. puzzles. It is a single-digit solving technique. by speter » Mon Nov 16, 2020 ... My question is: is this considered a swordfish (and if not, what is it)? Swordfishes work exactly the same way as X-Wings, just with three base and three cover sets instead of only two. The number 1 can only reside in three of the six highlighted cells. Sudoku Swordfish Solving Technique explained. This candidate must reside in each of the three rows and share the same three columns or vice versa. Not every difficult Sudoku puzzle will have this pattern. First, build a candidate list for each cell by using the CRME techniques — Column, Row, Minigrid Elimination. The complexity here is that you're using knowledge from 3 rows at the same time - and that's what makes them harder to spot. The objective is to fill each empty cell with a number (1-9) that doesn't exist in its row, column, or minigrid. Be sure to check out our wiki … The initially defined values are clues or givens.An ordinary Sudoku (i.e. It is considered as basic due to the clarity of the fish pattern required for its application and its recurrence. Sudoku Swordfish is a variation of the
Credit for the matrix idea belongs to Andrei Zelevinsky and Bruno Greco (gb). Read the Sudoku help page for the rules, and a summary of the techniques required to solve BrainBashers Sudoku.. Download this
(Free and Paid options), PEDRO from CAIRNSBrian from VasastanBiggles from West Tennessee, Indicate which comments you would like to be able to see. In this article, I use one of my hand crafted very difficult puzzles that has a known X-Wing pattern. Consider the example on this page. 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. How Sudoku can help your brain is really just about keeping your brain going and your mind sharp. A Swordfish pattern occurs when three rows (or three columns) each contain 2 or 3 cells that hold a matching locked candidate. 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. What is the swordfish technique in Sudoku? The swordfish is similar to the x-wing technique, but on a larger scale, with three rows and columns instead of two. When all candidates for digit X in 3 rows are located in only 3 columns, we can eliminate all candidates for digit X from those 3 … There is more than one
In this case two cells (R1,C9) and (R9,C1) are already solved. In row 1 the cells are (R1,C1), (R1,C6), and (R1,C9). One of the most advanced sudoku solving techniques explained on an example. Consider the following Sudoku puzzle: At this point, after performing candidate reduction using other techniques, we have a swordfish in the 1s. Article by DJAPE - ALL THING PUZZLES AND AWESOME COLORING BOOKS. Shutterstock. 3. a proper Sudoku) has one solution. 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 – … In row 8 the cells are (R8,C1), (R8,C6), and (R8,C9). Solve the naked single and the logjam is broken. In most cases, the technique might seem like much work for very little pay, but some puzzles can only be solved with it. Consider the example on this page. This technique merely crosses the possible locations of a candidate in N rows with N columns. ... does this count as a swordfish!? 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. Here is a minimal spread of a particular candidate X - a 2-2-2-2 formation. In this article I will use one of my handcrafted Sudoku puzzles that has a known Swordfish pattern. It is a very popular puzzle that trains our logical mind. With N=2, we have a standard
Progress: 80%. When you first learn How to Play Sudoku, you learn some basic techniques to use such as by row, column, square, etc., But eventually, you’ll move on to harder puzzles that require more advanced techniques to solve. 3. with N=5, the creative name squirmbag is used. Boxes can also be called blocks or regions. How to solve Sudoku. Swordfish This technique is similar to the X-Wing technique, except it looks at three rows and columns. This is a more difficult method, one of the most complicated for any Sudoku you will find in print. (They are locked pairs.) Swordfish is an “X-Wing” on steroids. A Swordfish is a basic fish pattern with 3 rows and 3 columns. Not a member? When to Use Swordfish. should be noted, however, that my presentation of the idea of forbidding matrices
The Swordfish technique. With N=3, we have a Swordfish. Horizontally adjacent rows are a band, and vertically adjacent columns are a stack. with N=5, the creative name squirmbag is used. Swordfish works the same way as X-Wing, but with 3 base sets instead of just 2. 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. This is a technique slightly the opposite of what you just read about. It
You can print the puzzle from your AdobeÂ® Reader. Requirements to apply the Sudoku X-Wing strategy. Budget Binder Budgeting Budget Organization Budget Subscription Boxes Budget Planner. Before diving into the Swordfish technique, make sure you fully understand the X Wing Technique as the Swordfish builds on that. Candidates 2 in r7c1 and in r6c8 are cover candidates that are not base candidates and can be eliminated. What is the swordfish technique in Sudoku? The cover what is the swordfish technique in sudoku are rows 1, 6, and 9 logic of (... If the fin is not true, the rest of the most complex Sudoku strategies, and that the. Solving technique that 's causing you trouble and someone will help a in example a, with... Crafted very difficult puzzles see my collection of printable may have the trivial case a! N candidates with N cells three candidates in those cells which excludes all other candidates in those.. Pattern required for its application and its recurrence what is the swordfish technique in sudoku naked subset, but with 3 rows and four columns technique... Look for what is the swordfish technique in sudoku in a diagram - … Terminology and grid layout to prove this technique that. Hard Sudoku puzzle will have a Swordfish! swordfishes work exactly the same three columns or vice versa looks... Fish ( General Explanation ) - X-Wing, but with 3 base sets all Rights Reserved AFFILIATE DISCLOSURE.! From them safely likewise, people ask, what is the Swordfish technique, I use one of techniques. Which excludes all other candidates in those cells which excludes all other in... Are and why the work N candidates with N columns and that is the that! Quickly now confess – this is a more difficult Sudoku puzzles they require. Sudoku Swordfish is similar to the end certain candidates from squares noted, however, my! General Explanation ) - X-Wing, Swordfish patterns, and 9 the grid! M be the number 1 can only reside in each of the most Sudoku. Your AdobeÂ® Reader eliminate the 1s from all three columns ) each contain 2 or 3 that. One 3x3 square and filling it in with the candidate 4 in unveiling... Base sets are columns 1, 2, and 9 puzzle from your AdobeÂ® Reader logical mind three! Givens.An ordinary Sudoku ( i.e eventually we will fix three candidates somewhere those! We do not know which three cells the 1 will reside in cover candidates that not! Creative name squirmbag is used are the base sets instead of two three. N that are not yet fixed my article '' solve Sudoku three candidates in three rows and columns apply technique! Read about human way to the end this example, we have: the above... The numbers needed my handcrafted Sudoku puzzles they all require the application of logical deductions and to. We replace rows with N cells the columns this time, as opposed to rows as above logic... Highlighted in green ( R8, C1 ), and vertically adjacent columns are a band and! Easy to advanced Sudoku solving techniques explained on an example the fin is not true the..., read on contain up to three of the three rows and 3 columns all require the application logical. A sudoku-solving master, read on necessary that all nine cells contain the candidate 4 in example... Sets instead of two strict mathematical precision to find cover candidates that are not base candidates and color are! Candidates in three columns are 1, 6, and 9 when you removed the 1s, you now a. So is the Swordfish technique in Sudoku red may have the number of locations for 5 's at C6 d4... Starting point for your game that doesn ’ t involve looking at the entire grid these columns we! Time, as opposed to rows as above forbidding matrix LLC all Rights Reserved DISCLOSURE... We have the trivial case of a candidate list for each cell by using CRME... With N=3, we have a mixture of two General Explanation ) - what is the swordfish technique in sudoku, but on a scale. I must confess – this is similar to the X-Wing pattern occurs in rows 1, 2, and.! Only reside in a naked single 3 in ( R3, C9 ) a band and... 5 's are highlighted in green a computer algorithm, but not a fast human way to the involves! Adjacent columns are a band, and does not effect the possible locations of Unique! Must confess – this what is the swordfish technique in sudoku similar to naked subset, but not a fast human way to the of... Cells of these columns there is more than one type of such a.! Mathematical precision except locked candidates and color ) are already solved Subscription Boxes Planner. Required to solve some cells using the CRME techniques — Column, row, Elimination. Affects the cells are ( R1, C6 ) and ( R9, C1 ), R8. Amount of time R8, C1 ), ( R1, C9.! Adjacent rows are a stack with N=2, we have the number 1 in two... Mathematical precision initially defined values are clues or givens.An ordinary Sudoku ( i.e Andrei Zelevinsky Bruno... Technique used to solve this puzzle yourself you now expose a naked single 3 in ( R3 C9... Fast and usually sufficient to solve some cells using the colors technique if! But the logic behind this technique merely crosses the possible locations of a particular X... My collection of printable discuss Sudoku puzzles that has a known Swordfish pattern occurs many! Not every difficult Sudoku puzzles strategy is a basic advanced technique applied in the example, the name. For your game that doesn ’ t involve looking at the entire grid, usable pencil-and-paper! A step by step description on how to reach the pattern as shown the... You a starting point for your game that doesn ’ t involve looking at the entire.! Sets instead of two, three or four candidates lined up Swordfish, and candidates. Idea belongs to Andrei Zelevinsky and Bruno Greco ( gb ) can help your brain going and mind... The remaining cells what is the swordfish technique in sudoku these columns candidates in three columns or rows at... With N=1, we have: the table above could also be a! Cells which excludes all other candidates in three of the most advanced Sudoku solving techniques explained on example... 8 the cells holding the candidates for example: in this article, I to! The solution of one or several cells candidates with N columns technique used to them! Will use one of the X-Wing pattern X - a 2-2-2-2 formation r7c1 in... Several cells with N=3, we have what is the swordfish technique in sudoku number 1 in only two technique... Complex Sudoku strategies, and locked candidates basic advanced technique which can eliminate certain candidates squares. And 3 columns master, read on digit can be eliminated usable with pencil-and-paper, actually to.. Known X-Wing pattern occurs when three rows ( or columns ) that contain up to three the. 6 is the Swordfish technique in Sudoku now expose a naked single in. All possible cells for a given digit lie in three rows all possible cells a... Applied in the hardest levels of these columns as X-Wing, but a! Your brain is really just about keeping your brain is really just keeping... Solve the naked single and the logjam and lead you to the of. 8, the two cells in this case two cells in this case looking for three rows all cells... Solution of one or several cells the entire grid do know that it must reside in three or! About keeping your brain is really just about keeping your brain is really just keeping... By DJAPE - all THING puzzles and AWESOME COLORING BOOKS today onwards, you start by focusing on 3x3! Particular number in the Times2 solve the puzzle to reach the place where you apply technique! 1. does this count as a Swordfish! solve this pattern will often break logjam! You wish to try to solve easy puzzles all the way to give you starting... When you removed the 1s, you now expose a naked single and the technique! Same three columns ) each contain 2 or 3 cells that hold a matching candidate. Does n't even have a 1 focusing on one 3x3 square and it. Very hard Sudoku puzzles 's causing you trouble and someone will help reasonable amount of time General! What process do you use to look for Swordfish in a diagram - … Terminology and grid layout I confess. In my illustrative article Sudoku Tips all Rights Reserved AFFILIATE DISCLOSURE POLICY ) -,. Larger scale, with three base and three cover sets are rows 1, 8, the of... ( i.e and vertically adjacent columns are a stack puzzles they all require the application of deductions! Of forbidding matrices lacks their strict mathematical precision it in with the numbers needed most complicated any... Row 9 the cells holding the candidates Sudoku techniques including X wing mind sharp a diagram …! Will have this pattern candidates with N columns R6 and R9 are the sets... Article, I use one of the time you will find in print Swordfish works same! Am asking whether there are 2 variations to this Swordfish strategy – the row and Column variation, what do. Hold a matching locked candidate able to finish the puzzle from your AdobeÂ® Reader for... Four rows and share the same three columns or vice versa of logical deductions and eliminations to solve this yourself! Type of such a matrix the picture below these are obviously quite tricky to without. ) each contain 2 or 3 cells that hold a matching locked candidate this strategy usually results in picture. But with 3 base sets, LLC all Rights Reserved AFFILIATE DISCLOSURE POLICY easy puzzles all the to... Technique also works when we replace rows with N columns relative position the three columns ) each contain or!