Question: When assembling stair treads and risers, is it better to have the tread tucked under the riser or have the riser tucked in between the tread and the stringer riser backing? I am inclined to think the former because that way the tread gets more framing support but the way my current stairs are assembled is the latter, hence my uncertainty. 

See picture.![enter image description here](https://i.stack.imgur.com/4Me0r.jpg)

Answer: 
We installed it so the tread goes under the riser. We installed hardwood stairs in our home and we cut the bottom of the riser at a slight angle to ensure that the front edge of the riser was always fully touching the tread so you couldn't see a gap between the riser and tread. 

I see a lot of places online that say to install the riser first and then install the tread (riser touching the stringers and tread in front of the riser), but I can't honestly think of a reason why it matters. Maybe someone else has a polarizing opinion, but I think either is fine.
Water flow over the tread which overhang these gaps you guys are talking about. If the tread happen to slope backward, no gap will prevent water from getting inside these gaps. Despite this fact, installing tread first then riser makes your life a whole lot better given that the tread is dead flat. Nevertheless, if you follow the max 1.5" max overhang, there's no possible way an average person or two can lift the tread up without the nose breaking first (doing the otherway). I've tried to do so myself even without he nail and glue in place. Anyhow, just make it look good.