13.7 kilometres. If you were running, that's the distance from Old Trafford to the Etihad Stadium and back, plus a little more.
It's also a quarter of a marathon, but that's how far Bernardo Silva ran on 3 January 2019 when Liverpool visited Manchester for a potential title decider.
Sergio Agüero scored a typically brilliant opener, Leroy Sané was electric and Fernandinho cut almost everything out at source, but it was the performance of Silva that took all the plaudits - there was not a blade of glass the Portuguese international failed to cover that night.