Mysterious stone spheres may have been used for Ancient Greek board game, study finds

Using artificial intelligence, a research team from the University of Bristol has presented new evidence that stone spheres found across Greek islands were used as counters in an ancient board game.

Bronze Age sites across the Aegean and Mediterranean have yielded a wealth of small, spherical stone artefacts, which for years have puzzled archaeologists. Now, using machine learning, a type of artificial intelligence (AI), a research team from the University of Bristol has presented new evidence that the stones were used as counters in an ancient board game.

These mysterious spheres have been discovered at Bronze Age settlements in Santorini, Crete, Cyprus, and other Greek islands, varying in size, colour, and stone material.

It has previously been suggested that the spheres were used as sling stones, tossing balls, or pieces for counting, record-keeping, or a board game.

Groups of spheres from Akrotiri. The research suggests that the stones may have been selected or worked to fit within two specific clusters of smaller and larger stones. IMAGE: Konstantinos Trimmis.

Researchers Dr Christianne Fernée and Dr Konstantinos Trimmis from the University of Bristol’s Department of Anthropology and Archaeology set out to investigate how the spheres may have been used and, last year, published a study showing that they varied in sizes within the clusters in which they were found.

In the latest study, published in the Journal of Archaeological Science Reports, the same team examined 746 spheres from the Bronze Age town of Akrotiri on the ancient island of Thera (now known as Santorini) – which was destroyed by a volcanic eruption in c.1600 BC and preserved under volcanic ash – to try and identify potential patterns within the clusters.

Using machine learning, Dr Fernée and Dr Trimmis discovered that the spheres were clustered into two major groups – one of smaller and one of larger stones. They found that the larger stones had been collected, whilst the others were worked to reduce their size.

According to Dr Ferneé, ‘this supports the hypothesis that they could have been used as counters for a board game… rather than a counting system for which you would expect more groupings.’

Stone slabs with cup marks (kernos) and their Reflectance Transformation Imaging analysis
IMAGE: Konstantinos Trimmis.

‘The social importance of the spheres, as indicated by the way they were deposited in specific cavities, further supports the idea of the spheres being part of a game that was played for social interaction,’ said Dr Trimmis. ‘This gives a new insight into the social interaction in the Bronze Age Aegean.’

The paper also puts forward that stone slabs called kernos, unearthed at Akrotiri and other sites across the Aegean, may represent the gameboard used together with the spheres. It proposes that the spheres could have been placed within the shallow cup-marks on the stone slabs.

The team now plan to use a similar methodology in order to assess the possible relationship between the spheres and the kernos. They also hope to use AI techniques to uncover how the game was played.