I decided to throw together a quick graphic comparing stopover and open-jaw rules for the most commonly earned airline miles for US travelers. I can't say how useful it will be, but hopefully it can be a quick guide to go with my more in-depth award ticket stopover and open-jaw master chart.
If it's useful I can add all airlines to the graphic to show which program is the most generous with their award ticket routing rules.
Simply follow the airline you want to compare around the circle to find out how many stopovers and open-jaws are allowed.
In general the airlines in the inner part of the chart (smaller circles) are more restrictive and the airlines on the outer part (larger circles) are more generous with more stopovers and/or open-jaws possible on award tickets.
I should also note that the loop represents a roundtrip award flight. The number of stopovers and open-jaws allowed are per roundtrip award ticket.
In either case it was fun to create and let me know what you think. If you want to see other graphics created share your ideas in the comments below!