you are +13 after this trade. 1+2 is 17 frames so it will trade with the opponent's jab after you hit them with df4, or if you block something that leaves them -7 (gigas df2 in this example) f2,1 doesn't always reach, (especially in this example vs gigas), but db1,2 ought to. I was just digging deep to do some cool combos. I was originally just looking for some unique path to a death combo... this isn't it, but it's interesting either way.