local function setPlayerSpeed(id)
    parse("speedmod " .. id .. " 50")
end

addhook("startround", "setSpeedForAllPlayers")
function setSpeedForAllPlayers()
    for i = 1, 32 do  -- assuming a maximum of 32 players
        if player(i, "exists") then
            setPlayerSpeed(i)
        end
    end
end

addhook("spawn", "setSpeedForSpawnedPlayer")
function setSpeedForSpawnedPlayer(id)
    setPlayerSpeed(id)
end