Difficulty tuning: slower grace ramp + harder default strategy (tangled) by riethmayer · Pull Request #46 · riethmayer/eureka

riethmayer · 2026-05-25T16:53:15Z

Follows up on production feedback that the game got easier as you climbed levels. Measured root cause: every per-level lever reduced difficulty — grace tiles grew as level − 1 (7 by level 8) and the only board strategy (scatter) is the most forgiving one we have.

Changes

1. Grace tiles ramp slowly (init-gameboard.ts)
Was level − 1. Now a slow step schedule:

level	grace tiles
1	0
2–4	1
5–14	2
15+	3

Grace only adds selectability, so solvability is unaffected.

2. New default strategy tangled (order-strategies.ts)
scatter (current default) is the most forgiving strategy; the harder existing ones (topDownRandom, bottomUpRandom) carry the "ready-made" top-cluster artifact. tangled peels low tiles first (fewer matches open at once → harder) but pulls each exposed upper tile down into the base, so the top never clusters.

Measured (branching = simultaneous legal moves; lower = harder; top-cluster = the artifact):

strategy	branching	forced-move %	top-cluster
scatter (was default)	9.4	3%	0%
bottomUpRandom	4.4	34%	100% ❌
tangled (new default)	7.6	3%	0% ✓

So tangled restores roughly the pre-scatter difficulty without the artifact. scatter and the others stay selectable (dev switcher / env override).

Notes

Strategy is still recorded per game; new games will record tangled. Production stays locked to the default (no player override).
yarn lint / type-check / vitest (106) / build all green.
Not merged — opening for review; say the word to ship.

Summary by CodeRabbit

New Features
- Added "tangled" board peel-order strategy
Enhancements
- Default board generation strategy changed from "scatter" to "tangled"
- Updated grace tiles difficulty scaling: 1 tile for levels 2-4, 2 for levels 5-14, 3+ for level 15+

Higher levels were getting easier, not harder: grace tiles grew as level-1 (7 by level 8) and the only strategy (scatter) is the most forgiving. Two changes give an upward curve: - Grace tiles ramp slowly: 1 from level 2, 2 from level 5, 3 from level 15+ (was level - 1). Grace only adds selectability, so solvability is unaffected. - New default strategy `tangled`: peels low tiles first (fewer matches open at once → harder) but disperses each exposed upper tile into the base, so the top never forms a "ready-made" cluster. Measured ~20% fewer simultaneous matches than scatter (branching 7.6 vs 9.4) with 0% top-cluster — restoring the old default's difficulty without its artifact. scatter and the others remain selectable.

vercel · 2026-05-25T16:53:20Z

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supabase · 2026-05-25T16:53:21Z

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coderabbitai · 2026-05-25T16:53:42Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: e33ee65d-b0be-45b5-88d0-650b73e50a18

📥 Commits

Reviewing files that changed from the base of the PR and between 426cb0c and 82c0464.

📒 Files selected for processing (6)

CLAUDE.md
src/utils/init-gameboard.test.ts
src/utils/init-gameboard.ts
src/utils/order-strategies.test.ts
src/utils/order-strategies.ts
src/utils/solvable-board.test.ts

📝 Walkthrough

Walkthrough

Introduces a new tangled board peel strategy as the production default, which disperses upper-layer tiles by pairing them with base tiles. Restructures grace-tile difficulty scaling to use fixed level-based thresholds (0, 1, 2, 3) instead of linear level - 1 calculation. Updates all related tests and documentation accordingly.

Changes

Tangled Strategy and Grace-Tiles Ramp

Layer / File(s)	Summary
Tangled Peeling Strategy `src/utils/order-strategies.ts`, `src/utils/order-strategies.test.ts`	Implements new `tangled` strategy that peels low-layer tiles and pairs exposed upper-layer tiles with base tiles to avoid top clustering. Updates registry and marks `tangled` as `DEFAULT_STRATEGY`. Test asserts new default.
Grace-Tiles Level-Based Ramp `src/utils/init-gameboard.ts`, `src/utils/init-gameboard.test.ts`, `src/utils/solvable-board.test.ts`	Replaces linear `level - 1` grace-tile logic with threshold-based counts: 0 (L1), 1 (L2–L4), 2 (L5–L14), 3 (L15+). Updates core logic, comments, and grace-tile expectations across test suites.
Strategy and Difficulty Documentation `CLAUDE.md`	Documents tangled as production default, clarifies adapter seam with selectable strategies, explains level-based grace-tile ramp and internal canonical fallback.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~25 minutes

Possibly related PRs

riethmayer/eureka#45: Both PRs modify src/utils/order-strategies.ts and its strategy setup—this PR adds the new tangled strategy and changes DEFAULT_STRATEGY to "tangled", building directly on the existing order-strategy adapter seam and prior "scatter" default.

Poem

🐰 A tangled web we weave with tile,
Low layers peeled with upper-tile guile,
Grace tiles scale in thresholds neat,
From level's ramp to harder beat,
New defaults set, the board's complete! ✨

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately summarizes the two main changes: a slower grace tile ramp and the adoption of a harder default strategy (tangled), which directly correspond to the primary objectives of this difficulty-tuning pull request.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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Commit unit tests in branch grace-tile-scaling

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src/utils/init-gameboard.test.ts

Oops! Something went wrong! :(

ESLint: 9.39.4

TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Object'
| property 'configs' -> object with constructor 'Object'
| property 'flat' -> object with constructor 'Object'
| ...
| property 'plugins' -> object with constructor 'Object'
--- property 'react' closes the circle
Referenced from: /.eslintrc.json
at JSON.stringify ()
at /node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2255:45
at Array.map ()
at ConfigValidator.formatErrors (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2246:23)
at ConfigValidator.validateConfigSchema (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2277:84)
at ConfigArrayFactory._normalizeConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3123:19)
at ConfigArrayFactory._loadConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3088:21)
at ConfigArrayFactory._loadExtendedShareableConfig (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3393:21)
at ConfigArrayFactory._loadExtends (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3261:25)
at ConfigArrayFactory._normalizeObjectConfigDataBody (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3199:25)
(node:2) ESLintRCWarning: You are using an eslintrc configuration file, which is deprecated and support will be removed in v10.0.0. Please migrate to an eslint.config.js file. See https://eslint.org/docs/latest/use/configure/migration-guide for details. An eslintrc configuration file is used because you have the ESLINT_USE_FLAT_CONFIG environment variable set to false. If you want to use an eslint.config.js file, remove the environment variable. If you want to find the location of the eslintrc configuration file, use the --debug flag.
(Use node --trace-warnings ... to show where the warning was created)

src/utils/init-gameboard.ts

Oops! Something went wrong! :(

ESLint: 9.39.4

TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Object'
| property 'configs' -> object with constructor 'Object'
| property 'flat' -> object with constructor 'Object'
| ...
| property 'plugins' -> object with constructor 'Object'
--- property 'react' closes the circle
Referenced from: /.eslintrc.json
at JSON.stringify ()
at /node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2255:45
at Array.map ()
at ConfigValidator.formatErrors (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2246:23)
at ConfigValidator.validateConfigSchema (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2277:84)
at ConfigArrayFactory._normalizeConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3123:19)
at ConfigArrayFactory._loadConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3088:21)
at ConfigArrayFactory._loadExtendedShareableConfig (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3393:21)
at ConfigArrayFactory._loadExtends (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3261:25)
at ConfigArrayFactory._normalizeObjectConfigDataBody (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3199:25)
(node:2) ESLintRCWarning: You are using an eslintrc configuration file, which is deprecated and support will be removed in v10.0.0. Please migrate to an eslint.config.js file. See https://eslint.org/docs/latest/use/configure/migration-guide for details. An eslintrc configuration file is used because you have the ESLINT_USE_FLAT_CONFIG environment variable set to false. If you want to use an eslint.config.js file, remove the environment variable. If you want to find the location of the eslintrc configuration file, use the --debug flag.
(Use node --trace-warnings ... to show where the warning was created)

src/utils/order-strategies.test.ts

Oops! Something went wrong! :(

ESLint: 9.39.4

TypeError: Converting circular structure to JSON
--> starting at object with constructor 'Object'
| property 'configs' -> object with constructor 'Object'
| property 'flat' -> object with constructor 'Object'
| ...
| property 'plugins' -> object with constructor 'Object'
--- property 'react' closes the circle
Referenced from: /.eslintrc.json
at JSON.stringify ()
at /node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2255:45
at Array.map ()
at ConfigValidator.formatErrors (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2246:23)
at ConfigValidator.validateConfigSchema (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:2277:84)
at ConfigArrayFactory._normalizeConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3123:19)
at ConfigArrayFactory._loadConfigData (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3088:21)
at ConfigArrayFactory._loadExtendedShareableConfig (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3393:21)
at ConfigArrayFactory._loadExtends (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3261:25)
at ConfigArrayFactory._normalizeObjectConfigDataBody (/node_modules/@eslint/eslintrc/dist/eslintrc.cjs:3199:25)
(node:2) ESLintRCWarning: You are using an eslintrc configuration file, which is deprecated and support will be removed in v10.0.0. Please migrate to an eslint.config.js file. See https://eslint.org/docs/latest/use/configure/migration-guide for details. An eslintrc configuration file is used because you have the ESLINT_USE_FLAT_CONFIG environment variable set to false. If you want to use an eslint.config.js file, remove the environment variable. If you want to find the location of the eslintrc configuration file, use the --debug flag.
(Use node --trace-warnings ... to show where the warning was created)

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vercel Bot deployed to Preview May 25, 2026 16:55 View deployment

riethmayer merged commit bc93a38 into master May 25, 2026
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Difficulty tuning: slower grace ramp + harder default strategy (tangled)#46

Difficulty tuning: slower grace ramp + harder default strategy (tangled)#46
riethmayer merged 1 commit into
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grace-tile-scaling

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