Discussion: What is the Hardest Position to Play in Sports?

I saw a little Twitter spat on NFL Twitter today. The discussion (turned into roast session, argument, bolstering competition, and outright lying, among other things, if you don't know Twitter by now maybe it's just best to stay ignorant) entailed if you had one play, one opportunity, to play for an NFL team, would you gain a yard? Going up against guys that are 6'2" 245 ON AVERAGE that have played basically their entire lives sounds kind of daunting, yeah? Even to gain so much as 3 measly feet on a play, people are questioning their abilities and their durability. This got me thinking though, running back is a very tough position. You take a beating, have to know play calls, how to run, how to catch, and if your skills or health falter you risk your career at the NFL level. It's become the NFL position, other than kicker and punter really, with the highest turn-over rate (That's turn-over as in someone loses their job, not the football) and in my opinion, qualifies as one of the toughest positions to play in professional sport.

So I ask my audience, what do you think are the toughest positions in team sport to play? Taking into consideration the game knowledge required to play it, the abilities that are demanded of the position, the durability needed, and overall the chance of that position being overtaken by someone else, there's a lot to consider. Here are my Top 5, personally:

1. Running Back, Football

2. Catcher, Baseball

3. Quarterback, Football

4. Point Guard, Basketball

5. Goalie, Hockey

Honorable Mentions: Pitcher, Middle Linebacker, DB, Center, GK in soccer, scrum half in rugby

This list takes into account all the factors listed previously, as well as a bit of personal experience with a few of these positions (My knees are still sore from catching, or maybe that's just years of contact sport? I don't know.) Please let me know your personal stories, what you think are the toughest positions in your book, and just for funsies, let me know if you could gain a yard in the NFL if given one shot. Best answers will be featured in the ScorchCast, thanks everyone!

Burn Notice: 10/10 My knees continue to burn...