Simple 2x

minbet=1e-8
chance=49.5
bethigh=true
basebet=math.max(balance*1e-6, minbet)
nextbet=math.max(basebet, minbet)
multiplier= 2
maxbet=balance*1.10

function dobet()

   previousbet = previousbet or basebet
  if (win) then
    nextbet=math.max(basebet, minbet)
  else
    nextbet=math.min(previousbet*multiplier, maxbet)
  end

  -- Clamp values
  chance   = math.min(math.max(chance, 1), 98)
  nextbet  = math.min(math.max(nextbet, minbet), maxbet)
end