In the NFL draft, there's a reason 12 of the last 15 first picks have been quarterbacks and centers never go in the top 10.
Certain positions simply have more in-game worth than others, and teams understand that.
No, basing selections on positional value is not a draft law, and there are always exceptions to specific rules.
But let's break down positional value into tiers and explain the logic behind categorizing each position.
The quarterback is, indisputably, the most vital position in football. That's precisely why it belongs in a tier of its own.
Teams struggle mightily without a consistent quarterback under center—just ask the Kansas City Chiefs, Cleveland Browns, Oakland Raiders, Buffalo Bills, Jacksonville Jaguars, St. Louis Rams or Miami Dolphins.
No player can turn around an organization faster than the right quarterback.
Andrew Luck took a 2-14 Indianapolis Colts team with a questionable roster to the playoffs in 2012.
Robert Griffin III did the same with a lackluster Washington Redskins club.
The NFL is becoming pass-happier—the league's pass-to-run ratio has titled toward more passing in each of the last five seasons—thereby adding to a quarterback's value.
Quite the list of signal-callers.
Think Flacco doesn't belong?
His postseason stat line of 11 touchdowns to zero interceptions would beg to differ.
When drafting, a quarterback has the most positional worth.
If the quarterback is the most important position on the field, then protecting him must be important too.
With more passes being thrown than ever before, teams with sound offensive tackles make the lives of their quarterbacks easier.
Although some quarterbacks are proficient scramblers and can make offensive lines better with quick and confident decisions, every team should make protecting its quarterback a top priority.
Pressure can come from any defensive line position, but the most devastating sack specialists are edge-rushers, and that's who offensive tackles are tasked to stop.
Offensive tackles have tremendous positional value in the draft due to the direct impact they often have on the quarterback position.
Whether it comes from a 4-3 defensive end or a 3-4 outside linebacker, rushing the passer is instrumental to sustained success in the NFL.
Rarely, if ever, do teams piece together quality regular seasons or win Super Bowls with a lackluster pass rush.
It just doesn't happen.
Rattling the opposing quarterback is key, as it results in ill-advised reads, incompletions and turnovers.
With an added emphasis on passing the football in today's NFL, disrupting the quarterback has become even more vital.
That's why we've seen pass-rushing specialists like Aldon Smith and Bruce Irvin go in the top 15 of late.
Outside pass-rushers have a major effect on the game, thus leading to such a high positional value in the draft.
Quarterbacks need talented wide receivers.
We saw how critical fantastic wideout play is during the Baltimore Ravens run to the Super Bowl in 2013.
Mario Manningham, Victor Cruz and Hakeem Nicks were integral to the New York Giants' title in 2012.
Aaron Rodgers reaped the benefits of incredible pass-catching weapons like Greg Jennings, Donald Driver, James Jones and Jordy Nelson when the Green Bay Packers beat the Pittsburgh Steelers in 2011.
The more talented the receiver, the better in NFL's passing renaissance.
Individually, a wideout may not be able to impact a game more than 10 times and is dependent on the quarterback, but collectively, a receiving contingent has a significant impression on Sundays.
Lastly, the rulebook is tailored to help the offense, with defensive pass-interference calls and defenseless receiver flags being thrown frequently.
Receivers have a distinctly high positional value in the draft.
From calling the plays to listening to a quarterback's pre-snap audibles and adjusting his unit accordingly, the middle linebacker is the quarterback of the defense.
Upon the snap, the middle linebacker must take the correct angle to the football on running plays to avoid a huge gain, meet lead blocks head on to free teammates and drop into the middle of the field to cover the seam.
Oh, and he needs to be an effective blitzer as well.
A terrific middle linebacker has a drastic ripple effect on an entire defense.
Usually, the top defenses have a great one.
4-3 Outside Linebacker
With more nickel and dime defensive packages being forced onto the field by the NFL's spread offenses, the 4-3 outside linebacker is more vital than, say, 10 or 15 years ago.
The strong-side 'backer must be an effective blitzer, but he must have the ability to line up with tight ends.
On the weak side, a true playmaker is needed, someone who can play the run, sift through traffic, get sideline-to-sideline quickly and comfortably drop into coverage.
Believe it or not, each season, a sound 4-3 outside linebacker is becoming more essential for teams running that defense.
Although a cornerback's job is to slow down receivers—and more receivers are being put on the field than ever— its positional value isn't as high as it once was.
Simply put, due to innovative spread sets, receivers are going to get open. Yes, having a Darrelle Revis or Richard Sherman exponentially helps a defense, but with motions, trip formations and rub routes, a fine cornerback can be relatively negated throughout the course of a game.
A cornerback is at the mercy of the wide receiver he's covering, someone who's dependent on the signal-caller throwing the football. Therefore, a cornerback—over the long haul—doesn't have as much impact on a game as positions like quarterback, wide receiver or pass-rusher.
Also, today's rules make it so difficult for a cornerback to make plays on a receiver or the ball.
Yes, finding a good one is a luxury, but the positional value isn't there at the top of a draft.
A play-making safety can make a good defense great. From intercepting passes to jarring a deep ball loose to sneaking into the "box" on a running play, safeties undoubtedly have value.
However, a safety can essentially be phased out of a game by the opposition's offensive game plan.
Sure, if an offense has to tailor its attack to keep the ball away from Ed Reed, there's a value in that, but over the course of a safety's career, his game-by-game impact is relatively minimal, and teams can get by without an elite player at the position.
A center is the quarterback of the offensive line, usually a cerebral technician with a nice blend of power and agility to get to the second level and enough anchoring strength to deal with mammoth defensive tackles at the point of attack.
He must create a rapport with his signal-caller and the rest of the offensive line to be prepared for stunts and exotic blitzes.
But a center isn't dealing with the most threatening pass-rushers on each play, and often gets help from neighboring guards in pass protection and when an "A" gap run is called.
Tight ends are morphing into huge, athletic and ultra-versatile game-changers. Every team uses them differently and some more than others, but a mismatch-creating tight end is becoming a trendy aspect of new age, spread offenses.
Also, hard-nosed blockers will never lose their worth, although running is sparser than ever.
Still, their positional value in the draft has never been high, and it shouldn't be.
They're more of a novelty than anything else.
Defensive tackle is a thankless position. Statistics are typically far from gaudy, and there's bound to be a collision on every play.
Having a penetrating and disruptive interior defensive lineman is the ultimate novelty for a defense, because it provides edge-rushers more one-on-one opportunities.
However, teams can win with willing, block-demanding big-bodies in the later rounds who aren't necessarily "elite" talents.
Football is a game won in the trenches, and guards definitely have worth. They're usually the guys pulling on power running plays, and they battle with beefy defensive tackles.
But because they aren't blocking premier pass-rushers in space and implement a variety of double-teams, they're reasonably interchangeable and replaceable, thus making their value somewhat low despite being a part of an essential group.
Running backs used to have the most positional value in the NFL; now they have the least.
With countless tales of late-round running backs emerging as productive feature backs, taking a running back early is widely considered a waste of a pick, or at least, a supreme luxury.
Also, running back's short shelf lives and propensity to get injured due to continual punishment haven't helped their value and have led to running back committees becoming a logical trend.