Sphere Trace Solver (BETA)

The board is a 5×5 grid of 25 hidden cells. Each cell belongs to exactly one ship (or is blue/empty). Ships are horizontal or vertical contiguous segments with no overlap:

• Teal — length 4, always present, worth 20 sp/cell
• Green — length 3, always present, worth 35 sp/cell
• Yellow — length 3, always present, worth 55 sp/cell
• Orange — length 2, always present, worth 90 sp/cell
• Rare ships — length 2 each, worth 76–500 sp/cell (Light 76, Dark 104, Red 150, Rainbow 500); 0 variable rares in 6-color, 1 in 7-color, 2 in 8-color, 3 in 9-color
• Blue — all remaining cells are empty, worth 10 sp/cell

Click budget: ship hits are free. Only hitting a blue (empty) cell costs from your budget of 4 blue clicks.

Extra Chance: if you’ve hit fewer than 5 ship cells total, each blue click extends the game (the game doesn’t end). Once you’ve hit 5 ship cells, Extra Chance shuts off — the next blue you click ends the game immediately. Use your remaining budget wisely.

Perfect game: use constraint inference to find all blue cells before hitting 5 ships, then collect all remaining ship cells for free.

The solver tracks which board arrangements are consistent with everything you've revealed so far. The Boards consistent count updates after each click.

Phase 1 — Extra Chance available (ships hit < 5):
While Extra Chance is active, the solver tries to find blue (empty) cells before hitting 5 ships, so you can collect all remaining ship cells for free afterward.

Recommendations come from the following sources, tried in order:

• policy — a precomputed policy table, looked up for the current board state
• heuristic — a learned scorer used when the policy table doesn't cover the current state; balances between P(blue), the information gain from a cell, the value of a cell, and finding ships. See “What are all the different numbers?” below for the scoring terms.
• greedy fallback — emergency fallback if solver data couldn't be loaded

Phase 2 — Extra Chance off (ships hit ≥ 5):
The next blue click ends the game. The solver switches to a separate learned scorer to maximize your remaining SP. If any cell is guaranteed to be a ship (P(blue) = 0 across all consistent boards), it is always recommended first — ship hits are free and don't cost budget. Source shown as v11p2 in Phase 2.

Cell overlays — shown on unrevealed cells when enabled in the Cell Overlays panel:

• P(B) — probability this cell is blue (empty), as a percentage. High = likely safe to click in Phase 1; low = likely a ship and good to target in Phase 2.
• EV — expected SP from clicking this cell, averaged across all consistent board arrangements. Most useful in Phase 2 to prioritize high-value ships.
• Score — composite heuristic score used to rank cells. Only shown when source is heuristic or v11p2. Higher is better.
• Tooltip — hover over any unrevealed cell to see a per-term breakdown of its Score (only when source is heuristic or v11p2).

Heuristic scoring terms — visible in the per-cell tooltip hover:

• t_blue — P(blue): probability this cell is empty.
• t_info6 / t_gini — information gain: how much clicking this cell is expected to reduce uncertainty about the remaining board. Higher = this click would reveal more about ship positions.
• t_ev / t_var_sp — expected value of this click: how much SP it is likely to yield, accounting for both the average and the variance across consistent board arrangements.
• t_rare_id — bonus for cells likely to help identify which rare color(s) are on this board.