Having had both successful and unsuccessful periods in your past. (Cambridge Dictionary)
Having a pattern consisting of alternating squares of different colours. (Oxford Dictionaries)
Marked by periods of varied fortune or discreditable incidents. (Oxford Dictionaries)
If a person or organisation has had a chequered career or history, they have had a varied past with both good and bad periods. (Collins Dictionary)
Something that is chequered has a pattern with squares of two or more different colours.
Round chequered pattern – racing card template vector image.