How do I add value in my wins leaderboard?

The leaderboard script is this:

function CreateStats(NewPlayer)
    local MainStats = Instance.new("IntValue")
    MainStats.Name = "leaderstats"
    MainStats.Value = 0
    local PointsValue = Instance.new("IntValue")
    PointsValue.Name = "Wins"
    PointsValue.Value = 0
    PointsValue.Parent = MainStats
    MainStats.Parent = NewPlayer
    return MainStats
end

game.Players.ChildAdded:connect(CreateStats)

And the win giver script is this

return function(winner)

end

What do i have to put in the second line so a player gets 1 win if they win a game?