From Longman Dictionary of Contemporary Englishan even chancean even chancePOSSIBLEa situation in which it is just as likely that something will happen as not happen I think we have an even chance of winning. We knew there was an even chance that the operation would fail. → even
Examples from the Corpus
an even chance• There is a suggestion that offspring do not have an even chance of inheriting a trait from either parent.• There was always better than an even chance of something like this happening. 