....a simplistic conceptual of how I prefer to drain a non-naturally occurring punchbowl [one I build from scratch], would be as follows;
1] Take a flat site and then fill and raise all the edges up in a circular form or with maybe a hint of squarish if you prefer.
Leave the front edges lower than the back, like a bowl that tilts forward.
If the site allows for excavation to achieve the same result, then by all means do and then proceed to...
2] Imagine the green as the face of a clock with the centerline running thru the six and terminating in the center.
Now imagine a slice or section of the green that includes approximately the area between the 8 and 6:30, joining in the center......this represents the break or high point with a diminishing ridge to the center that seperates the water flow inside the green surface.
3] Now from this section and in a couterclockwise movement, decrease the green slope at a 1.5 to 2 % slope rate that continues in counterclockwise fashion until it comes around to where it started ....this is where the majority of the water exits the green surface [somewhere between eight and 9:30 ish.
4] What you are really trying to achieve is a continuous rate of drainage slope that almost pivots around itself with only one exit.....conceptually in plan it has a sliced nautilus shell resemblance.
5] One can now add all the bells, whistles and nuances they want ....the description I have tried to provide is the basic building block that I personally use and I am sure there are many other methods.
.....somehow writing this created a new recipe image in my mind of a sesame encrusted salmon with other bells and whistles...I'll post that next if it works out well.