Red oaks don't always have pointy leaves, but they do (almost) always show bristles at the tips of the lobes of their leaves. For example, Shingle Oaks and Blackjack Oaks are both in the red oak group, but they don't have particularly pointy leaves. If you look closely, you can see the bristles though (Shingle Oak leaves obviously don't have lobes, but do have bristles at the leaf tip)
Shingle Oak
Blackjack Oak
With seedlings, it gets much more complicated. Even the "pointy leaf" species of red oaks tend to have rounded leaves as seedlings. These are Northern Red Oak (Quercus rubra) seedlings:
A couple of years ago, we started working with a couple of researchers who were interested in studying the effects of some restoration work we recently started in a 3,000 acre oak forest near here. There are four species of oak (red, black, bur, and chinkapin) there, plus about 400 other species of plants. One of our most basic needs is to figure out which species of oak are regenerating (or not) and how it relates to our management activities (or not). They said that they could design a study to help get that answer, but they didn't know how to identify oaks to species as seedlings. My botanist friend said 'We can teach you that'. So, we took them out in the woods and, you know what, it WASN'T easy to tell the seedlings apart
, even with just four species that are very distinct as adult plants. I walked by the patch of seedlings in the picture above and said 'There's some chinkapins'. One of the researchers said 'How can you tell?' so I got down on my knees and said 'See how the lobes are somewhat rounded and don't have any bristles'. Oops!