I need help on making an while number value adding loop?

When the player touches the ball, it creates Number Value. What I want it to do is when the player touches ball, the number value will keep on growing to a bigger number. I also what it to stop in 2 ways. 1 if it reaches to 200, it stops counting. 2 when somebody else touches the ball, it stops counting the person number who previously touched it. I try to do the number the loop but I did not under stand what i did.

local BallTarget = game.Workspace.BallTarget
local PlayersName = game.Workspace.BallTarget.BillboardGui.PlayersName

BallTarget.Touched:connect(function(hit)
    if hit.Parent:FindFirstChild("Humanoid") and
game.Players:GetPlayerFromCharacter(hit.Parent) then
	PlayersName.Text = hit.Parent.Name
	BallTarget.Material = ("Neon")
    BallTarget.BrickColor = hit.Parent:FindFirstChild("Torso").BrickColor
		numvalue.Value = 0
		while true do
			number = numvalue.Value + 1
			print(number)
			wait(1)
		end
    end
end)

function BallTargethit(otherPart)
	if otherPart ~= nil and otherPart.Parent ~= nil and otherPart.Parent:FindFirstChild("Humanoid") then
		print("A player hit me!")
		if not BallTarget:FindFirstChild(otherPart.Parent.Name) then	
			local playerTag = Instance.new("NumberValue")
			playerTag.Parent = BallTarget
			playerTag.Name = otherPart.Parent.Name
		end
	end
end
	numvalue.Value = 0
	while true do
		number = numvalue.Value + 1
		Value = (number)
		wait(1)
	end

BallTarget.Touched:connect(BallTargethit)

Organizing Data

The easiest way to accomplish what you want isn't by using NumberValues, but rather by using a table (or more specifically a dictionary). This way you can assign a Key to the table for each player who touches the ball that holds a value equal to the number of seconds they have been touching it. All we need to do is check if the player's points have been set yet, and initialize them to zero if not:

local points = {}

Ball.Touched:connect(function(hit)
	local player = game.Players:GetPlayerFromCharacter(hit.Parent)
	if player and not points[player] then
		points[player] = 0
	end
end)

Adding Points

Now we'll need a loop to add points to the last person who touched the ball's score. We'll create a new variable called LastPlayerTouched that we will have update each time a new player touches the ball. Then we'll call a new function called AddPoints that takes one argument, the player. This function creates a while loop that will run until LastPlayerTouched is no longer equal to the argument player (i.e. when another player touches the ball):

local LastPlayerTouched = nil

local function AddPoints(player)
	while LastPlayerTouched == player do
		points[player] = points[player] + 1
		wait(1)
	end
end

Updating the Ball

Now all we need to is write a function that changes the Ball and BillboardGui to reflect the player who is currently earning points:

local PlayersName = game.Workspace.BallTarget.BillboardGui.PlayersName

local function UpdateBall(player)
	PlayersName.Text = player.Name
	BallTarget.Material = ("Neon")
	BallTarget.BrickColor = hit.Parent:FindFirstChild("Torso").BrickColor
end

Putting it all Together

local PlayersName = game.Workspace.BallTarget.BillboardGui.PlayersName
local LastPlayerTouched = nil
local score = {}

local function AddPoints(player)
	while LastPlayerTouched == player do
		points[player] = points[player] + 1
		wait(1)
	end
end

local function UpdateBall(player)
	PlayersName.Text = player.Name
	BallTarget.Material = ("Neon")
	BallTarget.BrickColor = hit.Parent:FindFirstChild("Torso").BrickColor
end

Ball.Touched:connect(function(hit)
	local player = game.Players:GetPlayerFromCharacter(hit.Parent)
	if player and not points[player] then
		points[player] = 0
	end
	if player and LastPlayerTouched ~= player then
		LastPlayerTouched  == player
		AddPoints(player)
		UpdateBall(player)
	end
end)