Analysis Transparency

This page explains how move quality, accuracy, and labels are produced—including limits.

1) Accuracy formula

Move accuracy is derived from centipawn loss (CPL): the difference between the engine's best move and the move played. Lower CPL means better practical accuracy.

Accuracy = 100 × e−0.0001 × CPL²

This creates gentle penalties for small slips and steep penalties for large tactical misses. It mirrors how mistakes feel in real games.

2) Move classifications

ChessIQ classifies each move by evaluation loss so players can see what changed without decoding jargon.

BestExcellentGoodInaccuracyMistakeBlunder

3) Special labels

Special labels flag practical moments where context matters more than raw CPL.

Brilliant

Rare move that combines tactical value with practical surprise.

Great

Strong move in a critical position where alternatives were weaker.

Miss

A notable chance that was available but not played.

Forced

Only move that keeps the position stable or avoid immediate loss.

Checkmate

Mate found or prevented in a concrete tactical sequence.

4) Weighted accuracy and mercy rule

Not every move carries equal importance. Critical positions are weighted more than routine recaptures. ChessIQ also applies a mercy rule to prevent one collapse from making an otherwise solid game look artificially hopeless. The intent is honest reflection, not score inflation.

5) Depth presets

Fast and Balanced are practical defaults for everyday review. Deep, Ultra, and Mega search further, but require more time and battery. On mobile, lower presets are usually the best tradeoff.

6) Honest limits and edge cases

  • Engine evaluations can shift at higher depth, especially in sharp tactical positions.
  • Any single-number summary hides nuance; use labels and lines together, not in isolation.
  • Browser performance differs by device, so analysis speed and depth consistency can vary.
  • ChessIQ explains decisions, but it does not replace human judgment or coaching context.

Want a quick overview before diving into formulas?

See features