How chess is helping rehabilitate prisoners at HMP Wandsworth

43 teams from 31 countries competing in an online chess contest spanning the globe. The difference is all of the players are behind bars.

Four of them are in Wandsworth Prison, one of the largest jails in England and Wales and one of nine now running chess clubs.

Advocates claim that taking part in the game can play a role in rehabilitating inmates for life outside, as well as providing a way out of an often violent prison culture.