The careers of most actors will last only a year, according to a study of more than 2 million film stars.

The analysis also found both men and women will be busiest in the earliest stages of their career, before falling out of favour.

The mathematicians behind the study, from Queen Mary University of London, said their findings would help predict – with 85 per cent accuracy – whether the career of an actor has peaked, or if they should expect further success down the line.

Their findings have been published in the journal Nature Communications.

“Only a select few will ever be awarded an Oscar or have their hands on the walk of fame, but this is not important to the majority of actors and actresses, who simply want to make a living,” study co-author Oliver Williams said.

“Our results shed light on the underlying social dynamics taking place in show business and raise questions about the fairness of the system.”

The team analysed data from the Internet Movie Database (IMDb) on the careers of 1,512,472 actors and 896,029 actresses worldwide from 1888, when the first film was made, to 2016.

About 69 per cent of actors and 68 per cent of actresses had careers lasting just one year, with prolonged success the exception not the norm.

The researchers observed “hot” and “cold” streaks, with actors more likely to work in a year if they worked the year before, and most success early in their career.

The total number of jobs in an actor’s career appears to be linked to a “rich-get-richer” phenomenon, with the best-known actors getting the most jobs, they also found.

The researchers believe these trends mean they can predict whether an individual’s “annus mirabilis” – the year when they gained their most film credits – has already passed.

“Based on our findings, we have then constructed a statistical learning model that predicts with up to 85 per cent accuracy whether an actor or actress is likely to have a brighter future, or if the best days are, unfortunately, behind them,” the researchers said.

“While we expect refined versions of the prediction model to give even higher accuracy, it is worth noting that actors with long latency periods who then experience late comebacks are rare but intrinsically difficult to predict.”

-AAP