Problem with my allplayersDead variable?

Basically, a part of my script (lines 44-85) isn't working. I want it to check if all players died in the game, but all it does it continue after everyone dies. I don't know why, because it checks if "dead >= #game:GetService("Players").NumPlayers", but it still won't work. Help?

Error: ServerScriptService.Main:54: attempt to compare number with nil

local serverStorage = game:GetService("ServerStorage")

local maps = serverStorage:WaitForChild("Maps"):GetChildren()
local statusText = serverStorage:WaitForChild("statusText")

while wait(1) do
    for intermissionTime = 10, 1, -1 do
        statusText.Value = intermissionTime .. " until a new round starts!"
        wait(1)
    end

    statusText.Value = "Choosing a map..."
    wait(3)

    repeat
        chosenMap = maps[math.random(1, #maps)]
    until chosenMap.Name ~= oldMap

    statusText.Value = "The chosen map is " .. chosenMap.Name .. " by " .. chosenMap.Creator.Value .. "!"

    local chosen = chosenMap:Clone()
    chosen.Parent = workspace
    wait(3)

    for waitTime = 5, 1, -1 do
        statusText.Value = "Teleporting players in... " .. waitTime
        wait(1)
    end

    for i, v in pairs(game:GetService("Players"):GetPlayers()) do
        local spawns = chosen:FindFirstChild("Spawns"):GetChildren()
        v.won.Value = false
        v.Character.Humanoid.WalkSpeed = 0
        v.Character:MoveTo(spawns[i].Position)
    end

    wait(3)
    statusText.Value = "All players have 60 seconds to finish. Go!"

    for i, v in pairs(game:GetService("Players"):GetPlayers()) do
        v.Character.Humanoid.WalkSpeed = 16
    end
	
    winner = ""
    dead = 0
    allplayersDead = false
    local players = game.Players:GetPlayers()
    
	for _, player in pairs(players) do
        local living = Instance.new("BoolValue", player.PlayerGui)
        living.Name = "Living"
    end
        
	while wait(1) and roundTime > 0 and allplayersDead == false do
    	for _, player in pairs(players) do
        	if player ~= nil then
                if player.PlayerGui:FindFirstChild("Living") == nil then
                    dead = dead + 1
                end
                if dead >= #players then
                    allplayersDead = true
                    return {}
                end
        	end
        end
        dead = 0
        statusText.Value = roundTime .. " seconds remain!"
        roundTime = roundTime - 1
    end

    repeat
        wait()
    until roundTime == 0 or winner ~= "" or allplayersDead == true

    playerWin = nil
    oldMap = chosenMap.Name
    chosenMap:Destroy()

    if winner ~= "" then
        statusText.Value = winner.Name .. " has won!"
        winner.leaderstats.Points.Value = winner.leaderstats.Points.Value + 10
        wait(3)
    elseif allplayersDead then
        statusText.Value = "Everyone has died..."
        wait(3)
    elseif roundTime == 0 then
        statusText.Value = "The round time is up!"
        wait(3)
    end
end

The script at the end, along with being quite ineffecient, is too complicated. As BlueTaslem said, there can be a better way with a simplier script.

Normally i'd take out most of the variables you have here, but i kept in the most possible because it seems you prefer ineffeciency.

Anyway, a very simple way to get the players playing the game is to parent their characters elsewhere where you can separate them from the non-playing players. You will have to parent them back afterwards.

(I'd perhaps make this more effecient now that you told me you prefer anything and that this way was the only way you knew, but SH wouldn't help me.)

--Previous lines excluded for obvious reasons
    winner = ""
    dead = 0
    allplayersDead = false
    roundTime = 60
    local players = game.Players:GetPlayers()
    for _, player in pairs(players) do --This is meant to be done once when all players enter
        local living = Instance.new("BoolValue", player.PlayerGui)
        living.Name = "Living"
    end
        while wait(1) and roundTime > 0 and allplayersDead == false do
            for _, player in pairs(players) do
		if player ~= nil then --If the player leaves during game
                if player.PlayerGui:FindFirstChild("Living") == nil then
                    dead = dead + 1
                end
                if dead >= #players then
                    allplayersDead = true
                    return {}
                end
		end
            end
            dead = 0
            statusText.Value = roundTime .. " seconds remain!"
            roundTime = roundTime - 1
	end

    repeat
        wait()
    until roundTime == 0 or winner ~= "" or allplayersDead == true

    playerWin = nil
    oldMap = chosenMap.Name
    chosenMap:Destroy()

    if winner ~= "" then
        statusText.Value = winner.Name .. " has won!"
        winner.leaderstats.Points.Value = winner.leaderstats.Points.Value + 10
        wait(3)
    elseif allplayersDead then
        statusText.Value = "Everyone has died..."
        wait(3)
    elseif roundTime == 0 then
        statusText.Value = "The round time is up!"
        wait(3)
    end
end