...struggle to throw the ball on time, on the money, to the right guy.
Really good article about Dak Prescott breaking down one play of one game.
The line that really stands out to me: "See a little, see a lot; See a lot, see a little."
What does that mean?
It means this: for many pass concepts (let's say, Y Cross where the Y is on the left and crossing to the right), there are one or two defenders the QB has to "read" to determine where to go with the ball. Let's say the QB recognizes that it's a "middle field closed" cover 3 look (one centerfield safety, with CBs each responsible for a third) with 4 under. The QB might (slyly, without giving it away) zero in on what the right CB is doing pre-snap (let's say he's not press). But he's really going to read the CF safety because he decides it's time to go for a chunk play.
If the middle safety sniffs out the crosser is coming and doesn't get depth (looking to pick the cross), and the playside corner is staying on top of the WR running the "clear out" go route up the right sideline, the QB has one of two choices: rip the backside deep post to the 4th option on the concept (which is a location between the left hash and the center of the field, 35 to 40 yards downfield) or hit the checkdown. (It's too late to throw the quick out to the slot WR on the right side.)
The QB is banking on the #1 WR on the left hand side getting inside leverage on the left CB, running down the pass and using his body to shield/screen the left CB from getting a hand on the ball, if the gap between the WR and the CB gets small. The QB throws the ball with the expectation that the WR is going to win and gap the DB. If he takes the time to SEE that the WR is gapping the DB...too late. The timing is now ruined.
So by "seeing a little" (the CF safety stays flat-footed at the snap), the QB has created an opportunity to see the O gain a lot of yards, if not a TD. (Show me them TDs.)
On the flip side, if the QB tried to simultaneously watch all 7 pass defenders and all 4 receivers running routes...forget about it. Too much stimulus, too much info to take in, too little time to do it. The pass has to be out in 2 seconds, maybe 2.5 seconds for a chunk play like throwing the backside post on Y Cross. Trying to read the "whole" field results in a play that gains little to no yardage, or has little to no probability of success.