Practice Sudoku techniques on real candidate states.
Train the recognition step that is easy to skip when you only solve complete puzzles. The Academy combines the original frozen 40-drill Technique Lab with 32 additional source-derived Swordfish and Skyscraper states, for 72 verified drills across nine techniques.
Start the Sudoku Technique Academy
Every drill shows a real candidate state instead of a decorative example. Select the cells that make the pattern valid, check your choice, and read the elimination explanation. Hint and Reveal stay available, but using either marks that attempt Assisted so your Clean mastery remains an honest measure of independent recognition.
What the 72-drill curriculum covers
The Academy is deliberately ordered from local deductions to patterns that require comparing candidate positions across several rows or columns. Foundation work starts with Naked Single, Hidden Single and Locked Candidate. Set work moves into Naked Pair, Hidden Pair and Naked Triple. Fish work combines the existing X-Wing material with newly verified Swordfish states. The Links track adds Skyscraper, a single-digit pattern where two strong candidate pairs share a base and the two roof candidates jointly eliminate a target.
The original 40 Technique Lab drills remain byte-for-byte frozen from the earlier Sudoku mastery release. V0.147 does not rewrite those answers or loosen their old QA. Instead, it layers 32 new advanced states on top: 16 Swordfish and 16 Skyscraper. Each advanced technique is balanced across Easy, Medium, Hard and Expert source pools, with four drills from each difficulty for each technique.
Why candidate-state practice is different from another Sudoku puzzle
A complete Sudoku asks you to manage many tasks at once: maintain candidates, choose where to scan, remember recent placements and decide which method is promising. That is useful, but it makes technique recognition hard to isolate. A candidate-state drill removes most of that search overhead. You can focus on one question: which cells actually form the deduction, and what candidates can be removed because of it?
This is especially useful for patterns such as X-Wing, Swordfish and Skyscraper. Memorizing a diagram is not enough. The important skill is checking the structural conditions: how many candidate positions occur on each base line, whether the positions line up in the required columns or rows, and whether an actual elimination target exists outside the source pattern.
How Swordfish is verified here
For a row-based Swordfish, one candidate digit must be confined to two or three positions in each of three rows, and the union of those positions must occupy exactly three columns. That confinement means the digit must appear somewhere in those three columns inside the three source rows, so the same digit can be removed from candidate cells in those columns outside the source rows. Column-based Swordfish uses the same rule with rows and columns reversed.
The V0.147 bank is not labeled from a stored answer flag alone. Its generator starts from the existing verified Sudoku source bank, independently recomputes candidates from the givens, detects valid Swordfish structures, and records the exact source and elimination cells. The committed verifier separately recomputes candidates and the pattern constraints again before accepting every drill.
How Skyscraper is verified here
A Skyscraper uses two rows or two columns where the same candidate appears exactly twice. One occurrence in each pair lines up on a shared base line. The other two occurrences are the roofs. At least one candidate cell that can see both roof cells must exist; that shared peer cannot contain the candidate because one of the two roof positions must eventually be true.
The trainer asks you to select the four structural source cells rather than simply click the elimination target. That forces you to identify the reason for the deduction. Reveal then marks both the source pattern and affected target cells, making it possible to compare your visual scan with the verified structure.
Clean and Assisted mastery
Not every successful drill should count the same. A correct first recognition without Hint or Reveal is stored as Clean. If you request a Hint, reveal the pattern, or need additional attempts, the completion is kept as Assisted. Assisted work is still useful and remains in local history, but it cannot inflate the Clean count. This mirrors the broader DailyBrainArc approach of separating independent performance from help-assisted practice.
Technique statistics stay browser-local. The Academy records attempts, solved drills, Clean solves, Assisted solves, recent drills and a small per-technique summary. It does not claim an IQ score, clinical result, population percentile or universal Sudoku ranking.
Use the tracks instead of random drilling
Foundation is the place to start if candidate notation still feels slow. Sets focuses on pairs and triples. Fish groups X-Wing and Swordfish so you can compare two-line and three-line confinement. Links isolates Skyscraper. All 72 mixes the curriculum when you want recognition practice without knowing the technique in advance.
The Recommended next field uses your local Academy history to point toward an under-practiced or lower-Clean technique. It is intentionally simple and transparent rather than a black-box difficulty score.
Daily Academy versus the regular Daily Sudoku
The Daily Academy is a separate date-stable technique drill. Reopening it on the same date selects the same one of the 72 states, and its streak lives inside specialist Academy history. It does not replace the normal date-stable full Sudoku and it does not alter the site's Today’s 6 lineup.
Where the puzzles come from
DailyBrainArc already carries 160 verified 9×9 Sudoku source grids: 40 each for Easy, Medium, Hard and Expert. Each source has an independently checked unique solution. The classic 40 technique drills were extracted from those sources in the earlier Sudoku mastery release. V0.147 keeps that frozen material intact and derives only the 32 new advanced states from the same committed source bank.
This provenance matters because an attractive candidate diagram can still be a bad teaching example if its candidate marks are impossible under the givens or if the advertised elimination does not follow from the pattern. The generator and verifier therefore reconstruct candidate masks from the board instead of trusting copied notes.
A practical learning loop
Start with a track and solve several drills Clean. When one pattern repeatedly needs Hint, stay on that track until you can identify the source cells without help. Then return to a full Sudoku and use Auto Notes only if you want candidate support. The existing Technique button can explain the supported next logical step through X-Wing; the Academy is where you deliberately practice the broader pattern-recognition curriculum including Swordfish and Skyscraper.
If your goal is simply to play, skip the curriculum and choose Easy, Medium, Hard or Expert Practice. If your goal is to understand why a candidate can be removed, the Academy gives you the more focused workflow.