The total of 40 points has attained a mythical status for Premier League clubs battling against relegation.
While history has shown that this tally is no guarantee of avoiding relegation, more often than not, it has been enough to stay up.
What history tells us
Since the league was cut to 20 teams in 1995/96, the average points required to avoid the drop has been much lower than 40.
Over the past 23 seasons, the 18th-placed team, the highest to go down, have averaged 35.6 points.
So, 36 points would have been enough to stay up on at least 11 occasions, as Southampton did in 2017/18.
Teams with 37 points would have retained their Premier League status in 16 of the past 23 seasons.
West Bromwich Albion's 34 points in 2004/05 make them the team with the lowest total to remain in the Premier League.
Exception to the rule
The mythical 40-point barrier was not enough for West Ham United in 2002/03. The Hammers went down despite accruing 42 points, the highest for a relegated side.
Points for 18th-placed teams