local players = {"master39","BombBloke"}  -- Fill this table however you like.

commands.scoreboard("objectives add Kills totalKillCount")  -- Sample objective.
commands.scoreboard("objectives setDisplay sidebar Kills")  -- Makes the counter visible to players (once they start).

local maxVal = 100  -- Highest value you expect a player to reach.

local function getKillCount(playerName)
        if not commands.xp("0 "..playerName) then return 0 end  -- In case the player is not online.

        local minGuess, maxGuess, curGuess = 0, maxVal, math.floor(maxVal / 2)

        while curGuess >= minGuess and curGuess < maxGuess do
                if commands.testfor("@a[name="..playerName..",score_Kills="..tostring(curGuess).."]") then
                        -- Score is equal to or less than curGuess.
                        maxGuess = curGuess
                        curGuess = minGuess + math.floor((maxGuess - minGuess) / 2)
                else
                        -- Score is greater than curGuess.
                        minGuess = curGuess
                        curGuess = math.max(minGuess + 1, minGuess + math.floor((maxGuess - minGuess) / 2))
                end
        end

        return curGuess
end

-- A primitive score display loop:
while true do
        term.clear()
        term.setCursorPos(1,1)
        for i = 1, #players do print(players[i]..": "..getKillCount(players[i])) end
        sleep(30)  -- Or however many seconds you want between updates.
end