I am slowly learning to ID the flyers...
We can now shoot 6 mallards here (used to be 4) so now Mallard and Blacks at low light can be a real challenge... so far has never been an iuuse, I have only one limited out on Mallards (last year, I got 2 pair) and only once limited out on Blacks (monday of this week)
As far as Pintails hens, Blue wing and even greenwings, they all look so similar in the evening, hell I have shot black ducks that magically became teal once retrieved they just seemed much further away.