Technically, you are deferring the choice on first coin toss. I'm sure it's never happened, but you could defer in first half, letting other team say, "we will receive." Then let's say you have the lead but a 30 mile an hour wind picks up. Second half you may choose to kick anyway. You aren't required to receive, but it would require a strange issue for you to choose to kick...maybe your QB had a sudden bout of diarrhea...haha. The weird part that I wonder about because it's never happened is after you say, "we choose to kick," would ref turn to the team who had no choice, and even though they will receive, would they also get to choose the direction? Interesting scenario that will probably never happen, and if it did, I'll bet my mortgage the NFL refs screw it up somehow.