  Individuals have an intuitive perception of what makes a good coincidence.
Though the sensitivity to coincidences has often been presented as resulting
from an erroneous assessment of probability, it appears to be a genuine
competence, based on non-trivial computations. The model presented here
suggests that coincidences occur when subjects perceive complexity drops.
Co-occurring events are, together, simpler than if considered separately. This
model leads to a possible redefinition of subjective probability.
