If you can't find a sports score app that supports pop-up window mode, you can try to convert one that you like to add support for pop-up window mode with this app.
MW Pen App Enabler
https://forums.androidcentral.com/e...i.xperiacle.multiwindow.enable&token=tRz-nSWL
There are some things you need to know BEFORE doing this so be sure to read the app description before you decide to use it.
One thing is that you will no longer be able to update the sports app as is if you "pop-up enable" it. You will have to uninstall it first, reinstall the updated version, then go through the process of converting it to a pop-up app again.
Not typically a huge deal, just a few extra steps, but can be a pain if you converted a lot of apps.