{
 "grid_size": 9,
 "polyominos": [
  {
   "tiles": [
    [
     0,
     3
    ],
    [
     1,
     3
    ]
   ],
   "piece_type": "MOVABLE",
   "poly_id": 0,
   "color": [
    0,
    110,
    0
   ]
  },
  {
   "tiles": [
    [
     7,
     6
    ],
    [
     7,
     7
    ]
   ],
   "piece_type": "MOVABLE",
   "poly_id": 1,
   "color": [
    0,
    110,
    0
   ]
  },
  {
   "tiles": [
    [
     5,
     7
    ],
    [
     5,
     8
    ],
    [
     6,
     8
    ]
   ],
   "piece_type": "MOVABLE",
   "poly_id": 2,
   "color": [
    0,
    110,
    0
   ]
  },
  {
   "tiles": [
    [
     3,
     1
    ],
    [
     3,
     2
    ],
    [
     4,
     1
    ]
   ],
   "piece_type": "MOVABLE",
   "poly_id": 3,
   "color": [
    0,
    110,
    0
   ]
  },
  {
   "tiles": [
    [
     0,
     5
    ],
    [
     1,
     5
    ],
    [
     1,
     6
    ]
   ],
   "piece_type": "MOVABLE",
   "poly_id": 4,
   "color": [
    0,
    110,
    0
   ]
  },
  {
   "tiles": [
    [
     0,
     8
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     1,
     7
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     1,
     8
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     3
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     4
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     5
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     6
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     7
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     2,
     8
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     3,
     4
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     3,
     5
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     4,
     4
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     5,
     4
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     5,
     5
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     6,
     7
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     7,
     2
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     8,
     2
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     8,
     6
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     8,
     7
    ]
   ],
   "piece_type": "BARRIER"
  },
  {
   "tiles": [
    [
     8,
     8
    ]
   ],
   "piece_type": "BARRIER"
  }
 ],
 "level_color": [
  0,
  110,
  0
 ],
 "meta": {
  "generator": "mutate_harden",
  "preset": "9x9/5",
  "tier": "medium",
  "seed_optimal": 23,
  "harden_seconds": 240,
  "harden_restarts": 4,
  "hard_target": 33,
  "brutal": false,
  "soft_flaws": [],
  "hard_flaws": [],
  "beautify": {
   "removed": 0,
   "filled": 4
  },
  "taste": {
   "score": 3,
   "verdict": "tidy",
   "summary": "The board has a strong central structure, but a stray dot at [6,7] and a small notch at [7,2]-[8,2] make it look slightly machine-generated.",
   "issues": [
    {
     "kind": "random_dot",
     "cells": [
      [
       6,
       7
      ]
     ],
     "note": "Lone barrier dot floating in the lower right quadrant."
    },
    {
     "kind": "near_miss",
     "cells": [
      [
       6,
       7
      ]
     ],
     "note": "The dot is only one cell away from the shell-connected wall at (8,7) and (8,8) and the piece C."
    },
    {
     "kind": "ragged_shell",
     "cells": [
      [
       7,
       2
      ],
      [
       8,
       2
      ]
     ],
     "note": "Small 2-cell protrusion on the right edge that feels like a notch."
    }
   ],
   "suggest_fill": [
    [
     7,
     7
    ],
    [
     7,
     8
    ]
   ],
   "suggest_remove": [
    [
     6,
     7
    ],
    [
     7,
     2
    ],
    [
     8,
     2
    ]
   ],
   "model": "gemma4:31b"
  },
  "space": {
   "optimal": 30,
   "states": 45894,
   "dead_frac": 0.929,
   "optimal_lines": 481451040,
   "progress_frac": 0.322,
   "fatal_frac": 0.339,
   "fatal_merge_frac": 0.921,
   "forced_frac": 0.533,
   "survive_random": 0.0,
   "mean_branching": 6.1,
   "solvable_frac": 0.071,
   "min_carry": 10,
   "carry_frac": 0.333
  },
  "id": "daily_2026-10-20_medium",
  "date": "2026-10-20",
  "band": "medium",
  "difficulty_score": 0.412,
  "optimal_len": 30,
  "title": "Oct 20",
  "rev": "beeb0f5a"
 }
}