Sudoku isn't just about filling in numbers. Master these strategies — from naked singles to X-Wing — and you'll solve expert puzzles in minutes, not hours.
I've solved thousands of Sudoku puzzles. Literally thousands. I know this because at some point I started timing myself, and then I started tracking completion rates, and before I knew it I had a spreadsheet. That's the kind of person Sudoku turns you into — someone who optimizes their puzzle-solving workflow like it's a production deployment.
Here's what I've learned after all those grids: most people who say they're "bad at Sudoku" aren't bad at logic. They're bad at strategy. They stare at a partially filled grid, try random numbers until something sticks, and then declare the puzzle broken when they hit a contradiction three minutes later. That's not solving — that's gambling with digits.
Sudoku is a game of elimination, pattern recognition, and systematic technique. Every single puzzle — from the gentlest newspaper easy to the most sadistic expert grid — can be solved without ever guessing. That's the beauty of it, and that's what I want to show you today.
Whether you've never touched a Sudoku or you're stuck at intermediate difficulty wondering how people solve expert puzzles so fast, this guide covers every strategy you actually need, why each one works, and when to deploy it.
This isn't hyperbole. Sudoku appears in over 2,000 newspapers globally. It's been played on every continent, translated into every language (well, the numbers translate themselves), and spawned an entire competitive circuit with world championships. More people solve a Sudoku on any given day than play chess, complete a crossword, or do any other logic puzzle.
Why? Three reasons:
The rules fit in one sentence. Fill every row, column, and 3x3 box with the digits 1 through 9, no repeats. That's it. No vocabulary required, no cultural knowledge, no math beyond counting to nine. A five-year-old can understand the rules. A fifty-year veteran can still find challenge in them.
The difficulty scales infinitely. An easy Sudoku gives you 35+ pre-filled cells and can be solved with a single technique. An expert puzzle gives you 22 cells and demands five or six different strategies layered on top of each other. The skill ceiling is remarkably high for something that looks so simple.
It's perfectly portable. A Sudoku puzzle is a 9x9 grid. It fits on a napkin, a phone screen, a newspaper column, or a browser tab. You can solve it in two minutes or twenty. You can stop mid-puzzle and come back hours later. There's no opponent to wait for, no time pressure unless you impose it, and no equipment beyond something to write with.
That combination — simple rules, deep skill curve, total portability — is why Sudoku has outlasted every puzzle fad since it went global in 2004. Wordle was fun for a few months. Sudoku has been fun for two decades.
Before we dive into strategies, let me make sure we're on the same page about the mechanics. Every valid Sudoku puzzle has exactly one solution. This is important — it means you never have to guess. If a puzzle has multiple solutions, it's a poorly constructed puzzle, full stop.
The grid has 81 cells arranged in 9 rows, 9 columns, and 9 boxes (the 3x3 sub-grids). Every row must contain the digits 1-9 exactly once. Every column must contain the digits 1-9 exactly once. Every box must contain the digits 1-9 exactly once.
A cell's "peers" are all the other cells that share its row, column, or box. Each cell has exactly 20 peers. When you place a number in a cell, that number is eliminated as a possibility from all 20 of its peers. That's the entire game — cascading eliminations until every cell has exactly one possibility left.
Now let's talk about how to make those eliminations systematically.
If you're just starting out, you only need two techniques. Seriously. These two strategies alone will carry you through every easy puzzle and most medium ones.
A naked single is the simplest possible deduction: if a cell can only contain one digit, then that digit goes in that cell.
How do you know a cell can only contain one digit? By elimination. Look at the cell's row, column, and box. Cross off every digit that already appears in any of those three groups. If only one digit remains, you've found a naked single.
Example: suppose a cell is in a row containing 1, 3, 5, 7, 8, a column containing 2, 4, 6, 9, and a box containing 1, 2, 3. The row eliminates 1, 3, 5, 7, 8. The column eliminates 2, 4, 6, 9. That leaves... nothing? Wait, let me recount. The row eliminates five digits, the column eliminates four more, that's nine eliminated — impossible. Let me fix that example.
Okay, realistic example: a cell's row has 1, 3, 5, 7. Column has 2, 4, 8. Box has 6, 9. Together those eliminate 1, 2, 3, 4, 5, 6, 7, 8, 9 — wait, that's all nine. That means the cell already has all its peers filled. Let me think about this more carefully, because getting the example right matters.
Here's a proper one. Row contains: 2, 5, 8. Column contains: 1, 3, 7. Box contains: 4, 6. Together they eliminate 1, 2, 3, 4, 5, 6, 7, 8. Only 9 remains. Place the 9.
The key insight: you're not searching for the right number. You're eliminating the wrong ones until only one survives. This mental shift — from "what goes here?" to "what can't go here?" — is the single biggest improvement most beginners can make.
A hidden single is the mirror image of a naked single. Instead of asking "what can go in this cell?", you ask "where can this digit go in this row/column/box?"
If a specific digit can only fit in one cell within a row, column, or box, then that digit must go in that cell — even if the cell has other candidates too.
Example: you're scanning box 5 (the center box) for the digit 7. You check each empty cell in the box. Most of them already have a 7 in their row or column, eliminating 7 as a possibility. Only one empty cell in the box can accept a 7. That cell gets the 7.
Hidden singles are "hidden" because the cell might seem like it has multiple possibilities. You might look at it and think "this could be 3, 7, or 9." But if you check the whole box for where 7 can go, you realize this is the only cell — so it must be 7.
The scanning technique: for each box, systematically ask "where does 1 go? Where does 2 go? Where does 3 go?" all the way through 9. This methodical approach catches hidden singles that you'd miss by just staring at the grid hoping for inspiration.
On easy puzzles, you'll enter a satisfying loop:
When this cascade works smoothly, it's one of the most satisfying feelings in puzzle-solving. Cells fall like dominoes, the grid fills itself, and you feel like a genius. Enjoy it while it lasts — medium puzzles will humble you quickly.
Before we move to intermediate strategies, we need to talk about pencil marks (also called candidates or notes). This is the single most important skill upgrade in Sudoku.
Pencil marks are small notations in each empty cell showing which digits are still possible there. Instead of keeping all this information in your head, you write it down.
On paper, you write tiny digits in the corners or center of each cell. In a good browser-based Sudoku, you toggle candidate digits on and off with a click or keypress.
Why pencil marks matter: every strategy beyond naked singles and hidden singles operates on the relationships between candidates across multiple cells. Without pencil marks, you can't see these patterns. It's like trying to play chess without seeing the board — technically possible, but absurdly hard.
When to write them: I pencil mark the entire grid at the start. Some people prefer to do it on-the-fly, only marking cells they're actively analyzing. Either approach works, but full pencil marks let you spot patterns you weren't looking for.
The maintenance rule: every time you place a digit, immediately update the pencil marks in all 20 peer cells. Remove the placed digit from their candidate lists. This maintenance is crucial — stale pencil marks will mislead you and cause errors. Good browser implementations do this automatically, which is one of the huge advantages of playing digitally.
Here's my honest opinion: if you're solving Sudoku on paper and refusing to use pencil marks because it feels like "cheating," you're handicapping yourself for no reason. Every competitive Sudoku solver uses pencil marks. Every world championship finalist uses pencil marks. It's not cheating — it's the game.
You'll know you need these when you hit a puzzle where you've found all the naked and hidden singles, updated your pencil marks, and... nothing. The grid stares back at you. Every cell has two or three candidates, no cell has one, and no digit has a unique home in any group.
Welcome to intermediate Sudoku.
A naked pair is two cells in the same row, column, or box that contain the same two candidates and nothing else. For example, two cells in row 3 that both contain only 7.
Here's the logic: one of those cells must be 4 and the other must be 7 (or vice versa). We don't know which is which, but we know for certain that 4 and 7 are "claimed" by those two cells. Therefore, we can eliminate 4 and 7 from every other cell in that row.
This is powerful because it often triggers a cascade. Removing candidates from other cells can create new naked singles or hidden singles that restart the solving chain.
Naked triples work the same way with three cells and three candidates. The cells don't each need to contain all three candidates — they just need to collectively contain exactly three candidates across three cells. For example, cells with 5, 8, and 8 form a naked triple for 8.
The counterpart to naked pairs. A hidden pair occurs when two digits can only appear in two cells within a row, column, or box.
Example: in column 7, the digit 3 can only go in cells at rows 2 and 6. The digit 8 can also only go in those same two cells. Those two cells form a hidden pair — they must contain 3 and 8 (in some order). You can eliminate all other candidates from those two cells.
Hidden pairs are harder to spot than naked pairs because the cells might have lots of other candidates cluttering your view. You have to look past the noise and notice that two digits are restricted to the same two locations.
This technique exploits the overlap between boxes and lines (rows or columns).
If a digit's candidates within a box are all confined to a single row, then that digit must appear in that row within that box. Therefore, you can eliminate that digit from the rest of the row (the parts outside the box).
Example: in box 1, the digit 6 can only appear in row 1 (let's say cells at columns 1 and 3). Since box 1 must contain a 6, and it can only be in row 1, the 6 in row 1 must be in box 1. Eliminate 6 from all other cells in row 1 (those in boxes 2 and 3).
The reverse also works: if a digit in a row is confined to a single box, eliminate it from other cells in that box.
This technique feels like magic the first time you see it. The interaction between two different types of groups (boxes and lines) creates information that neither group provides alone. It's a beautiful piece of logic.
This is essentially the inverse of pointing pairs and works on the same principle. If all candidates for a digit in a row or column fall within a single box, that digit can be eliminated from other cells in that box.
Example: the digit 5 in row 4 can only appear in columns 4, 5, or 6 — all within box 5. Since row 4's 5 must be in box 5, you can eliminate 5 from all other cells in box 5 (those in rows 5 and 6).
Together, pointing pairs and box/line reduction let you squeeze information out of the intersection geometry of Sudoku's constraint groups. They're the bread and butter of intermediate solving.
Now we're in the territory where puzzles fight back. These techniques require careful analysis of candidate patterns across the entire grid. They're harder to spot, harder to execute, and immensely satisfying when they work.
The X-Wing is the first "fish" pattern, and it's the gateway to advanced Sudoku. Here's how it works:
Pick a digit. Find two rows where that digit has exactly two candidate positions. If those candidate positions line up in the same two columns, you've found an X-Wing.
Visualization: imagine the four cells form the corners of a rectangle. The digit must appear exactly twice in this rectangle — once in each row, at opposite corners. This means the digit is "locked" into those two columns. You can eliminate that digit from every other cell in those two columns.
Example: digit 3 can only appear in columns 2 and 7 of row 1, and digit 3 can also only appear in columns 2 and 7 of row 5. The X-Wing pattern tells us that 3 must be in one of two configurations: (row 1, col 2) and (row 5, col 7), or (row 1, col 7) and (row 5, col 2). Either way, columns 2 and 7 are accounted for. Remove 3 from all other cells in columns 2 and 7.
Why it's called X-Wing: if you draw lines between the diagonal pairs of the rectangle, they form an X. Honestly, I think someone just thought the name sounded cool. And they were right.
The Swordfish is the X-Wing's bigger sibling. Instead of two rows with two candidate positions each, you need three rows where a digit appears in two or three positions each, and those positions collectively span exactly three columns.
The logic is identical to X-Wing, just expanded: the digit must appear once in each of the three rows, within those three columns. So you can eliminate the digit from all other cells in those three columns.
Swordfish patterns are rare and hard to spot. I'd estimate I encounter one every 30-40 expert puzzles. When I do find one, it's always the key that breaks the puzzle wide open. They tend to appear in puzzles specifically designed to be difficult.
The XY-Wing is fundamentally different from X-Wing despite the similar name. It's about three cells with two candidates each, linked in a specific way.
You need a pivot cell with candidates {X, Y} that can see (shares a row, column, or box with) two wing cells: one with candidates {X, Z} and one with candidates {Y, Z}. The three cells form a chain of overlapping candidate pairs.
The logic: either the pivot is X or Y. If it's X, the {X, Z} wing becomes Z. If it's Y, the {Y, Z} wing becomes Z. Either way, one of the two wings must be Z. Any cell that can see both wings — meaning it shares a group with both — cannot be Z.
This is the first technique that feels like actual logical reasoning rather than pattern matching. You're constructing an argument: "if this, then that; if not this, then this other thing; either way, this conclusion holds." It's deductive reasoning in its purest form, and it's why advanced Sudoku is genuinely intellectually stimulating.
Beyond the named techniques, expert puzzles sometimes require coloring — tracing chains of implications through the grid. If cell A is X, then cell B can't be X, which means cell C must be X, and so on.
Simple coloring assigns two "colors" to the possible positions of a digit and follows the chain to find contradictions. If both colors reach the same cell, one of them is false, giving you information.
This technique is where Sudoku stops feeling like a puzzle and starts feeling like formal logic. I find it deeply satisfying, but I'll admit it's not for everyone. If you enjoy proof-based mathematics, you'll love coloring. If you prefer the visual pattern-matching of X-Wings and Swordfish, you might find coloring tedious.
Here's something most Sudoku apps get wrong: difficulty isn't about how many cells are pre-filled. A puzzle with 25 given digits can be easier than one with 28, depending on which cells are filled and what techniques you need to solve it.
Proper difficulty ratings are based on the most advanced technique required:
| Difficulty | Given Cells | Techniques Required | Solve Time (experienced) |
|---|---|---|---|
| Easy | 36-45 | Naked singles, hidden singles | 2-5 minutes |
| Medium | 30-36 | + Naked/hidden pairs, pointing pairs | 5-15 minutes |
| Hard | 27-32 | + Box/line reduction, naked triples | 10-25 minutes |
| Expert | 22-28 | + X-Wing, Swordfish, XY-Wing | 15-45 minutes |
| Extreme | 20-25 | + Coloring, chains, forcing nets | 30-90 minutes |
The best Sudoku generators rate puzzles algorithmically: they solve the puzzle using a hierarchy of techniques and rate it by the most advanced technique the solver needed. This gives you a consistent, meaningful difficulty progression.
A puzzle rated "expert" should require expert techniques. If you can solve an "expert" puzzle using only naked and hidden singles, the rating system is broken. This is one of the easiest ways to judge the quality of a Sudoku platform.
This is the hill I'll die on: you should never guess in Sudoku.
By "guess" I mean placing a digit without logical certainty, hoping it works out, and being prepared to backtrack if it doesn't. Some people call this "bifurcation" or "trial and error." Whatever you call it, it's not solving — it's brute-forcing.
Every properly constructed Sudoku puzzle can be solved using pure logic. If you reach a point where you feel like guessing is your only option, one of three things is true:
You're missing a technique. There's a deduction available that you haven't learned yet. This is the most common case, and it's why learning new techniques matters.
Your pencil marks are wrong. You made an error somewhere — placed a wrong digit or forgot to eliminate a candidate. Audit your work.
The puzzle is poorly constructed. It has multiple solutions, making pure logic insufficient. This is rare from reputable sources but common from low-quality generators.
I'll admit that competitive speed-solvers sometimes use educated guessing (specifically, Nishio — trying a candidate and seeing if it leads to a contradiction). But even that is a structured form of elimination, not random guessing. For learning and enjoyment, stick to pure logic. The satisfaction of cracking a tough puzzle through reasoning alone is worth the extra time.
I've taught Sudoku to enough people to know the patterns. These are the mistakes I see over and over:
Starting without scanning the whole grid. Don't dive into the first empty cell you see. Spend 30 seconds scanning the grid for easy wins — rows, columns, or boxes that are nearly complete. The digits with the most placements are your best starting points because they have the fewest remaining positions.
Forgetting to update pencil marks. You place a 7, then two minutes later you're confused because your pencil marks show 7 as a candidate in a peer cell. Every placement should trigger an immediate candidate update. Digital platforms do this automatically — another reason to play online.
Tunnel vision on one area. You find a useful deduction in box 3 and then spend five minutes staring at box 3 hoping for another one. Move on. Scan the whole grid after each placement. The cascade from your deduction might have opened opportunities on the opposite side of the board.
Not learning new techniques. If you can solve easy and medium but consistently fail at hard, the answer isn't "try harder." The answer is "learn pointing pairs." Each difficulty tier requires specific knowledge. Stubbornness doesn't substitute for technique.
Second-guessing correct placements. If you made a logically sound deduction, trust it. Don't erase it just because the grid looks weird or because you "have a feeling" it's wrong. Logic doesn't lie. Feelings lie all the time.
Once you're comfortable with the techniques, you might want to get faster. Competitive Sudoku solving is a real thing — the World Sudoku Championship draws participants from 30+ countries — and even casually, beating your personal best time is addictive.
Scan in order. Develop a routine: scan all boxes for hidden singles of digit 1, then 2, then 3, all the way to 9. Then scan rows. Then columns. Routine eliminates the "where should I look next?" hesitation that eats time.
Focus on high-frequency digits first. If you see that 7 appears six times on the grid, there are only three 7s left to place. Start there — fewer remaining positions means faster deductions.
Use keyboard input, not mouse. On digital platforms, selecting a cell and typing a number is significantly faster than clicking through a number pad. If the platform supports full keyboard navigation (arrow keys + number keys), use it.
Don't pencil mark everything at expert level. This is controversial, but many fast solvers skip full pencil marking on easier sections and only mark cells where they're actively working a technique. Full marking takes time. Selective marking saves time but requires you to keep more in your head.
Practice specific techniques in isolation. Find puzzles rated for a specific technique (many platforms let you filter by technique) and practice until you can spot the pattern instantly. Speed in Sudoku comes from pattern recognition speed, not from thinking faster.
I want to be careful here because the "brain training" industry makes absurd claims. So let's stick to what peer-reviewed research actually supports.
Cognitive engagement. A 2019 meta-analysis published in the journal PLOS ONE examined the relationship between puzzle-solving and cognitive function in older adults. The researchers found that regularly engaging with number and logic puzzles was associated with better performance on measures of attention, reasoning, and memory. The effect sizes were small but statistically significant.
The "use it or lose it" hypothesis. Longitudinal studies, including data from the ACTIVE trial (Advanced Cognitive Training for Independent and Vital Elderly), suggest that cognitive training can maintain processing speed and reasoning ability over a period of years. Sudoku isn't explicitly studied in most of these trials, but it exercises exactly the reasoning and working memory skills that the training targets.
Stress reduction. This one has less formal research behind it, but anecdotally and in several survey studies, puzzle-solving provides a state of focused attention similar to meditation. Psychologists call this "flow state" — you're too engaged in the puzzle to think about your inbox, your bills, or that awkward thing you said in 2014.
What the research doesn't say: Sudoku won't make you smarter. It won't prevent dementia (no activity has been proven to do that). It won't raise your IQ. Anyone making those claims is selling you something.
What Sudoku can do is keep your reasoning skills active, provide a daily dose of genuine problem-solving, and give you a screen activity that's actually mentally stimulating instead of passively consuming content. In 2026, that's worth something.
I solve one Sudoku puzzle every morning with coffee. It takes 5-15 minutes depending on difficulty, and it's become as routine as brushing my teeth. Here's why I think a daily puzzle habit is worth building:
It's a warm-up for your brain. Before I open my IDE or check email, I've already exercised logical thinking, pattern recognition, and focused attention. The mental transition from "just woke up" to "ready to think" is smoother.
It provides consistent progress. Unlike most games, Sudoku gives you measurable improvement over weeks and months. Your solve times drop. Your completion rate on harder difficulties rises. You spot patterns faster. The progress is slow but undeniable, and that's motivating.
It's a bounded commitment. One puzzle, done. Not an infinite scroll, not a multiplayer session that runs long, not a mobile game designed to never let you stop. A Sudoku puzzle ends, and you can move on with your day feeling accomplished.
Suggested progression for building the habit:
I have opinions about this.
Desktop is better for learning and hard puzzles. You have a bigger grid, a physical keyboard for fast input, and easier pencil mark management. When you're working through an X-Wing or coloring chain, screen real estate matters. The larger view lets you see the whole grid's candidate patterns at once.
Mobile is better for daily habit and easy/medium puzzles. It's always with you. Waiting for coffee? Solve a puzzle. Train delay? Solve a puzzle. The convenience factor is enormous for building a habit.
Browser-based is better than app-based. No download, no storage, no updates, no permissions. Open a tab, solve, close the tab. Your progress can be saved locally without creating an account or handing over your email address. Modern browser-based Sudoku is indistinguishable from a native app in terms of responsiveness and features.
The ideal setup: play on your phone for your daily easy puzzle, play on your desktop when you're ready to challenge yourself with expert grids.
If you've mastered standard Sudoku and want fresh challenges, the variant world is enormous and wonderful.
Normal Sudoku rules plus: groups of cells (marked with dotted lines) must sum to a given total. This adds arithmetic to the logic. You're not just eliminating digits by row/column/box — you're also constrained by sum requirements. A cage requiring a sum of 3 in two cells? Must be 2. A cage summing to 17 in two cells? Must be 9. The interplay between sum constraints and standard Sudoku logic is deeply satisfying.
The grid contains thermometer shapes. Digits along each thermometer must increase from the bulb to the tip. This adds ordering constraints that interact with the standard rules in surprising ways. If a thermometer spans from box 1 to box 4, the ordering constraint carries information across box boundaries that standard Sudoku doesn't provide.
Clues outside the grid tell you the sum of digits between the 1 and the 9 in each row or column. This variant requires you to simultaneously figure out where the 1 and 9 go and what sits between them. It's a completely different flavor of logic.
Circles with arrows extending from them: the digit in the circle must equal the sum of digits along the arrow. This creates fascinating cascading constraints, especially when arrows cross box boundaries.
These variants aren't just gimmicks — they're genuinely different puzzle experiences that exercise different logical muscles. If you love classic Sudoku, give Killer a try first. It's the most natural transition and adds a layer of mathematical reasoning that classic Sudoku doesn't touch.
Sudoku isn't the only puzzle game worth your time. Here's how it compares to other logic puzzles:
Sudoku vs Crosswords: completely different skills. Crosswords test vocabulary and cultural knowledge. Sudoku tests pure logic. Neither is "better" — they exercise different parts of your brain. If you want a puzzle that doesn't depend on knowing trivia, Sudoku wins. If you want a puzzle that expands your vocabulary, crosswords win.
Sudoku vs Kakuro: Kakuro is like Sudoku's math-loving cousin. It uses a crossword-style grid where you fill in digits that sum to given values without repeating. If you enjoy the arithmetic aspect of Killer Sudoku, Kakuro is your next stop. It's less well-known but has a devoted following.
Sudoku vs Nonograms (Picross): Nonograms give you number clues that reveal a hidden picture when solved. They're more visual and creative — the reward is seeing an image emerge. The logic is different: it's about counting and spacing rather than elimination. I alternate between Sudoku and Nonograms when I want variety.
Sudoku vs Minesweeper: Minesweeper is underrated as a logic puzzle. The advanced play is genuinely strategic, involving probability assessment and constraint satisfaction. But it has a luck element that Sudoku doesn't — some Minesweeper situations are genuinely ambiguous, requiring a guess. Sudoku never does.
Sudoku vs 2048: different categories entirely. 2048 is more of a strategy game with optimization and spatial reasoning. It's fun but doesn't have the same depth of technique that Sudoku offers. You can master 2048's core strategy in an hour. Sudoku's technique ladder takes months to climb.
The honest truth? Play all of them. Different puzzles on different days keeps things fresh. I rotate through Sudoku, Nonograms, and Minesweeper throughout the week, and each one feels better because of the variety.
Not all browser Sudoku is created equal. Here's what I look for:
Algorithmic puzzle generation with technique-based difficulty. The platform should generate unique puzzles rated by the techniques required to solve them, not just by given cell count.
Full pencil mark support. Toggle candidates on and off per cell. Auto-eliminate placed digits from peer cells. Highlight cells sharing a candidate. Without good pencil mark tooling, advanced techniques are impractical.
Keyboard navigation. Arrow keys to move between cells, number keys to place digits, a shortcut to toggle pencil mark mode. Mouse-only input is painfully slow.
Optional validation. Let me check for errors when I want to, not constantly. The red-highlight-on-every-mistake style kills the puzzle experience. I want to discover my errors through logic, not through the UI telling me I'm wrong.
Clean, distraction-free interface. No ads covering half the grid. No pop-ups begging for app downloads. No social features demanding I share my solve time. Just the grid, the tools, and the puzzle.
No account required. I should be able to open a tab and start solving immediately. Save my progress locally if you want, but don't make me create an account to play a free puzzle.
I want to end with something less technical.
In a world designed to fragment your attention — notifications, feeds, autoplay videos, infinite scrolls — Sudoku is one of the few screen activities that demands your complete focus on a single task. You can't half-solve a Sudoku while watching TV. You can't skim it. You either engage fully or you get nowhere.
That forced single-tasking is genuinely rare in 2026, and I think it's part of why Sudoku endures. It's not just a puzzle — it's permission to focus on one thing for ten minutes without guilt. Every other screen activity feels like it's competing for your attention with something else. Sudoku just... asks you to think.
I find that deeply valuable. Puzzle games in general share this quality, and if you haven't explored beyond Sudoku, there's a whole world of logic puzzles, strategy games, and brain teasers available for free in your browser — no downloads, no accounts, no distractions. Just you and the puzzle, the way it should be.
Now if you'll excuse me, I have an expert grid that's been taunting me since breakfast. That X-Wing isn't going to find itself.
Akousa