I never had a reason to drop Tyler from 4 bottles to 3, so I didn't. We were both happy with our routine and he always took his bottles without a problem. We got rid of them when we introduced whole milk at 1 yr, but like Natasha said, Tracey recommends getting rid of them by 2 yrs. When Tyler turned 1, we gave him whole milk in a bottle for one feed for a couple of days just to see if he liked it, and he did, so we started dropping bottles. We'd drop one, give his appetite several days to adjust, then drop another. Since we went pretty slowly, he never had a problem with night wakings from hunger. And in the beginning, he barely drank enough from the sippy, so we made sure to give him lots of other dairy foods during the day to make sure he was getting enough.