First downs, as in the first play in a series- not the reward for gaining 10 yards within four plays, are like first dates. First dates can set the tone for the rest of the relationship, much like first downs can set the tone for the rest of the series. Likewise, both are to be handled delicately to prevent a snowball effect of issues. Of course, first dates are reliant on one person interacting with another, whereas football has 22 moving pieces at once, but the comparison still holds true. So, what is it that I am getting at?
Obviously not every series begins with a pass, but when they do, it is key to understand the situation and handle it in the best way possible. Being that it is the first of four downs to gain ten yards, there is little rationale to get aggressive as a passer. Take what is given to you! If nothing is there, throw the ball away and get back in the huddle. It does not have to be complicated. Quarterbacks too often get caught up in wanting to go for what may seem like a big play instead of simply taking the chunk of yards right in front of their face. In theory it may sound like a wonderful idea, especially if you are losing at the time, but it is an unnecessary gamble.
That being said, do not immediatly look for the short yardage pass. A cornerback may blow an assignment or a receiver may create a ton of separation. Either way, much of what happens on a football field can not be predicted before the snap. I realize it may seem like I am making an obscure argument (if that is what you would like to call it), but let me expand on what I have said through GIFs.
Gambling certainly has its payouts, but at the same time, it is a mistake more often than not. Even the most talented of passers can look bad if they are throwing to windows that are nonexistent. For a number of reasons, Andrew Luck is a prime example of such. He may be one of the most accurate and talented passers in the league, but he made a number of poor decisions, even on first downs.
Below, Luck has Griff Whalen (No.17) open to his left. Luck even appears to look his way, but after evading a pass rusher, he decides to fire downfield to Reggie Wayne, who is not even remotely close to being open. Shame to be within 35 yards of the end zone, which is field goal range at the least, and throwing throw away the opportunity to score (literally).
On the play below, Luck has Stanley Havili open in the flats, but decides to force the deep throw to Darrius Heyward-Bey. That play was followed by a sack, then a run that did not earn a first down. Now, Luck is still one of the best quarterbacks in the league, but even he can get overzealous and ruin a drive.
On the other end of the spectrum, being too hesitant can hold the offense back. Below, Terrelle Pryor throws a short pass to Darren McFadden. The play goes for a decent gain, but in the next two plays, Oakland fails to get the first down. Although, had Pryor thrown to Jacoby Ford (No.12) on the slant, the play would have been a first down on first down and the drive would have continued.
So, if gambling is bad and being too passive restricts the offense, what is a good way to handle a first down passing situation? Below, Ben Roethlisberger scans the entire field, sees that nobody else is open, and throws a short pass for a few yards. Unlike Pryor, Roethlisberger did not have a better option. He took what was given!
Lastly, there is a good example to be made of Christian Ponder (yes, really). Below, Ponder is flushed out of the pocket, so instead of forcing a throw back to the middle of the field, Ponder simply throws the ball out of bounds and gets ready for the next plays.
As you can see, passing on first down is about balance. It is about understand the situation at hand and making sure to make the best of it. First down is not a down to try something risky just because you have three more downs. Reversely, first down is not a down to let good opportunities slip by because you are too scared to even look down the field.
It truly is as simple as taking what you are given. Of course, that could mean a number of things, but the point is to not purposely do too much or too little. First down is about being efficient, nothing more. As has been said plenty of times before, first down is about taking what is given.