Solver vs. Human Play in Crossplay

Cheating detection in Crossplay rests on a simple idea: solvers and people play differently, and that difference leaves a trace. Understanding how each one approaches a board explains why the detector compares your opponent's move against both, rather than just asking whether the move was “good.”

How a solver decides

A solver treats every turn as a search problem. It considers the full set of legal placements, scores each one, weighs what it leaves behind on the rack, and returns the highest-value option. It has no favorite words, no habits, and no blind spots. If an awkward two-letter hook in a cramped corner is worth the most points, that is what it plays — every time, without hesitation.

How people actually decide

Humans work from patterns and shortcuts. We spot familiar words, anchor on the first strong idea, and often stop searching once a play looks good enough. We miss legal words we have never used, overlook cramped angles, and take longer on hard boards than easy ones. That is not a flaw — it is what makes games human — but it produces a recognizable fingerprint that differs from a solver's.

Strong is not the same as suspicious

This is the distinction that matters most. Plenty of excellent moves are also popular moves: the obvious play that scores well and that most players would find. Those look human and score low. Suspicion rises only when a move is simultaneously near-optimal and the kind of choice people rarely make — the solver's pick that a person would usually walk right past.

What the detector compares

For a single move, the detector reconstructs the position, asks a Crossplay solver what the strong options were, and measures how close the observed play sits to that reference — then asks how often human players actually choose something that solver-like. The result is a read on the gap between the two, which is far more informative than raw move strength. And because one move is thin evidence, the same comparison across several turns is where a real pattern shows up.