why i cant change the Rank on the leaderboard when i get 10 Points?

i want to change the rank to beginner when a player get 10 points but the ranking does not change any help?

local player = game.Players.LocalPlayer

if player.leaderstats.Points.Value == 10 then
    player.leaderstats.Rank.Value = "Beginner"

end

and this is my leaderboard script

game.Players.PlayerAdded:Connect(function(player)

    local stats = Instance.new("Folder", player)
    stats.Name = "leaderstats"

    local Points = Instance.new("IntValue", stats)
    Points.Name = "Points"
    Points.Value = 0

    local Rank = Instance.new("StringValue", stats)
    Rank.Name = "Rank"
    Rank.Value = "Noob"

 end)