Well, It was not obvious, to ME!

I have figured out one move order puzzle and found an answer for another.

I have been using Wojo's Weapons as a guide for my new white openings (with Avrukh as backup). Wojo would enter the Queen's Gambit by 1.Nf3 d5 2.d4 Nf6 3.c4, and he would play 2.c4 against most other black responses. I think this move order is a way of avoiding both the QID and the Benoni.

Why does white play 3.Nf3 in the Slav? I know I get there, because I play 1.Nf3 and transpose, but 3.Nf3 is played 3 times more than 3.Nc3 after 1.d4 d5 2.c4 c6. The answer is that 3...dxc4 transposes into the QGA and most prefer 3.Nf3 to 3.Nc3 in the QGA.