If you have a preshot that is much lower than your +10 or +11, knowing why will help you decide whether or not to shoot. Some Lantus and Levemir users notice a dip at the end of the cycle, meaning that the preshot is always a bit lower than +10 or +11 (but usually still higher than the nadir – the cat dips to a nadir at mid-cycle, then rises, then dips again). If this is your cat’s pattern, then this type of dip is not a reason to delay a shot. On the other hand, if your cat has a bounce clearing and is still careening downhill at shot time (usually characterized by numbers that drop for the whole cycle, without a clear nadir), then you will want to take that into consideration as you make a decision about shooting. Know thy cat.