try this at 0.001

chance  = 24.975
nextbet = 0.00000001
prebet  = 0.00000001
bethigh = true
mick    = 0
lose    = 0
function dobet()
if win then
    mick += 1
    nextbet = 0.00000001
    lose    = 0
else
    lose += 1
end
if (math.fmod(lose,2)==0) then
    nextbet = previousbet*2
    if win then nextbet = prebet end
end
if (mick==2) then
  if (bethigh==true) then bethigh=false else bethigh=true end
  mick = 0
end
if balance > 1 then
    stop()
end
end