Football is the ultimate team sport, an 11-on-11 duel in which the whole truly is greater than the sum of its parts.
However, on any given Sunday, in any given matchup, there are any number of games within the game—matchups that go a long way toward determining each contest's winner.
As we head into a week of NFL games highlighted by a reunion in America's heartland, here's a look at the head-to-head battles that will define Week 7.
We might as well get this one out of the way, since it's the Week 7 equivalent of the elephant in the room.
On Sunday night, quarterback Peyton Manning will lead the undefeated Denver Broncos into Lucas Oil Stadium to battle the 4-2 Indianapolis Colts.
You see, Manning has a bit of history with the Colts.
Even after a performance in Week 6 in which Manning threw "only" two touchdown passes and failed to top 300 yards for the first time this season, the 37-year-old remains on a pace that will rewrite the record books at his position.
It will fall on the Colts defense to try to knock Manning off that pace.
The Indy defense has been the unsung hero of the team's hot start, ranking 11th in total defense (337.7 yards per game) and fifth against the pass (205.7 yards per game).
The Colts can take a page from, believe it or not, the Jacksonville Jaguars in this regard.
The Jaguars didn't sack Manning in Week 6, but they had some success in disrupting Manning by applying pressure.
That task will fall to linebacker Robert Mathis, who is tied for the NFL lead with 9.5 sacks. Mathis will be going against a Denver offensive line that is without Pro Bowl left tackle Ryan Clady.
The Colts will also no doubt pick the brains of Mathis, safety Antoine Bethea and wide receiver Reggie Wayne.
After all, each of those players either played with Manning or faced him daily in practice for years.
The insight they provide could prove invaluable in slowing down Manning's assault on the record books.
Of course, part of the success Peyton Manning has had in 2013 can be attributed to the wealth of talent the Broncos have in the passing game.
In other words, the Indianapolis secondary is going to have its hands full.
Cornerback Greg Toler, who will likely draw Decker in coverage, is going to have do better than his 82nd-place ranking in that regard at his position, according to Pro Football Focus (subscription required).
Toler's certainly going to have to improve on last week's performance. In the loss to the San Diego Chargers, both Toler and slot corner Darius Butler lost as many battles as they won.
However, the heaviest weight will fall on Butler and free safety Antoine Bethea.
Time and time again this year, Manning has responded to defensive pressure with quick passes over the middle to Welker and Thomas.
In this regard, the Colts would certainly benefit from the return of strong safety LaRon Landry this week.
PFF has graded Landry much higher in coverage than Bethea this season, and it's absolutely imperative that the Colts slow the Broncos passing game down between the hashes.
If they can slow Manning down, the Colts are going to have a real chance at pulling off the upset. Andrew Luck should be able to move the ball against a Denver pass defense that ranks dead last in the NFL.
Luck needs his defense to keep the team in the game.
As well as things have gone for the Indianapolis Colts, they've gone equally as badly for the Houston Texans.
After a 2-0 start, the Texans have dropped four in a row, culminating in a humiliating 38-13 loss to the St. Louis Rams in Week 6.
As if that wasn't bad enough, the Texans could be going into Arrowhead Stadium to face the undefeated Kansas City Chiefs with either T.J. Yates or Case Keenum at quarterback.
If the Texans are going to have a chance at halting their losing skid, they are going to need a lights-out performance from the Houston defense.
On defense in Houston, it all starts with end J.J. Watt.
The reigning NFL Defensive Player of the Year was invisible against St. Louis, failing to record any stats and logging only a single hit on quarterback Sam Bradford.
It's crucial that Watt make his presence known against Kansas City, whether it's denying running back Jamaal Charles the edge or getting in the face of quarterback Alex Smith.
Luckily for the Texans, at least the matchup appears to benefit Houston.
Eric Fisher was the first overall pick in 2013, and the youngster may one day be a dominant offensive lineman.
That day is not today, however. Fisher has struggled at right tackle, grading poorly in both run blocking and pass protection, according to Pro Football Focus.
Offensive guards are, in many respects, the Rodney Dangerfields of the NFL.
Although they bang away in the trenches play after play, very few are "name" players. They just don't get no respect.
For example, most fans outside of Cincinnati have no idea who Clint Boling is. In fact, many fans in Cincinnati have no idea who Clint Boling is.
For those who don't know, Boling is the third-year pro who starts at left guard for the Bengals.
He's also one of the best players in the NFL at what he does, ranking third among all guards in 2013, according to Pro Football Focus.
Boling's prowess will be put to the test this week against the Detroit Lions, as Boling will be tasked with fending off defensive tackle Ndamukong Suh.
Suh is the motor that drives the entire Detroit defensive line. If Boling can win the battle up front, then not only will he keep Suh off quarterback Andy Dalton but the Bengals should have success on the ground against a Detroit defense that ranks 29th in the NFL against the run.
Should Boling hold his own against Suh, it would also allow guard Kevin Zeitler and center Kyle Cook to double-team the much larger Nick Fairley inside.
This matchup between first-place teams is one of the bigger games of Week 7.
It's only fitting that it be decided by the biggest players.
Right now, you're probably wondering why the title of this slide doesn't read "Larry Fitzgerald vs. Richard Sherman."
The reason is simple: Fitzgerald is battling a sore hamstring, and even if he plays he won't be at 100 percent.
Just the threat of Fitz playing would likely get him a shadow job from Sherman. That leaves Brandon Browner matched up with second-year receiver Michael Floyd on the other side.
It's a battle that the Arizona Cardinals can win, and one that they must win if they are to have any chance of downing the Seattle Seahawks on Thursday night.
Granted, it isn't going to be easy. Browner may not be Sherman, but he's no slouch either. The third-year pro is a Pro Bowl-caliber defensive back, and at 6'4" and 221 pounds Browner is one of the NFL's biggest, most physical cornerbacks.
However, Browner is off to a shaky start this season. T.Y. Hilton of the Indianapolis Colts had his way with Browner in Week 6. According to Pro Football Focus, opposing quarterbacks have posted a passer rating above 90 while throwing at Browner this season.
Meanwhile, Floyd has picked up his pace recently for the Cardinals with Fitzgerald ailing, reeling in 15 passes for 192 yards and a score over the past three games.
The Cardinals are going to have to throw the ball to have a shot against the Seahawks, and making Floyd the focal point of the passing game in Week 7 gives quarterback Carson Palmer the best chance for success through the air.
After a hot start to the season the Miami Dolphins have cooled off, losing two straight heading into their bye week.
One of the Dolphins' biggest problems during their mini-slump has been a lack of pass protection for quarterback Ryan Tannehill. Through four games, the Dolphins have surrendered 24 sacks, the second-highest total in the NFL.
That makes it imperative that Miami gets better at pass blocking this week in an AFC East clash with the Buffalo Bills.
After a very rocky preseason, second-year pro Jonathan Martin has improved in that respect, at least somewhat. But, Martin still has surrendered six sacks this year, second most in the league.
It isn't going to get any easier for Martin in Week 7.
On Sunday, Martin will be tasked with stopping defensive end Mario Williams, who has already tallied eight sacks this season.
The Bills secondary has been ravaged by injuries and can be had through the air, but Tannehill can't complete passes from his back.
It will fall on Martin to keep Tannehill off it.
Through six games, Philadelphia Eagles running back LeSean McCoy is the leading rusher for the team leading the NFL in rushing.
McCoy has picked up 630 yards on the ground this season, giving the 25-year-old nearly a 100-yard lead on Arian Foster of the Houston Texans for the league's individual lead.
This week, the Eagles and that ground game will play host to the Dallas Cowboys in a battle for first place in the NFC East.
The Cowboys are a middle-of-the-pack run defense, ranking 14th in the NFL at 105 yards per game.
The leader of that defense, at least where shutting McCoy down is concerned, is middle linebacker Sean Lee.
After something of a slow start to the 2013 season, Lee has exploded of late, racking up an eye-popping 44 tackles over the past three games. Lee's 60 tackles on the year leads the NFC.
You can bet that the Eagles will bang away on the ground against Dallas, and how much success McCoy has against Lee may well determine whether the Cowboys leave Philly in first place or second.
The Green Bay Packers defeated the Baltimore Ravens 19-17 in Week 6, but that win came at a very high price.
Fellow wideout James Jones is also very iffy for Week 7 after spraining a ligament in his knee against Baltimore.
Unfortunately, it also robs the Green Bay passing attack of the varied weaponry usually at Rodgers' disposal, while painting a target on Nelson's back.
That target has a No. 23 on it.
With the Green Bay receiving corps banged up, it's a virtual certainty that cornerback Joe Haden will shadow Nelson all game long.
If the third-year pro is able to take Nelson out of the game, then tailback Eddie Lacy may be forced to carry the Green Bay offense once again against a Cleveland defense that has surrendered fewer than 100 yards a game on the ground in 2013.
Heading into the 2013 season, this game was circled on the calendars of many fans.
When the Baltimore Ravens and Pittsburgh Steelers lock horns, it's a knock-down-drag-out fight between mirror-image teams who genuinely don't like one another.
Some of the luster has been knocked from this prizefight by the two teams' combined record of 4-7 in 2013.
However, the Ravens are only a game back of the Cincinnati Bengals in the AFC North, and a proud Pittsburgh franchise isn't about to turn tail and call it a year.
If the Steelers are going to pull the "upset" at home, then there's one thing the Steelers have to do. It's something they haven't done consistently all season long.
Protect Ben Roethlisberger.
The Steelers traded for tackle Levi Brown a couple of weeks ago, in an effort to improve up front.
That idea is now toast. As Scott Brown of ESPN reports, the Steelers placed Brown on injured reserve with a torn triceps muscle.
That leaves Kelvin Beachum and Marcus Gilbert as the starting offensive tackles, as the Steelers have already demoted the woefully ineffective Mike Adams.
Sadly for Beachum and Gilbert, this week's matchup is a borderline nightmare.
In outside linebackers Terrell Suggs and Elvis Dumervil, the Ravens boast one of the top pass-rush duos in the National Football League.
Both Suggs and Dumervil rank in the top five at their position this year, according to Pro Football Focus. The pair has 12 sacks between them in six games.
It's crucial that the Steelers establish the run with tailback Le'Veon Bell to set up play action. Even then Pittsburgh is going to be forced to run a lot of two-route, "max protect" pass plays.
Big Ben had best be wearing his boogie shoes this week. He's going to be scrambling a lot.
Given that the New York Giants and Minnesota Vikings have combined to post a record of 1-10 this season, Monday night's matchup is hardly a "marquee" game.
The Minnesota Vikings made the playoffs a year ago, but the 2013 season has hardly gone according to plan. As Tom Pelissero of USA Today reports, Josh Freeman will make the third starting quarterback the Vikings have had in six games this season.
The Vikings may not know who their quarterback is, but there's no doubt who will be taking handoffs from him.
Running back Adrian Peterson will be the focal point of the Vikings offense, and shutting "All Day" down is the key to the Giants getting their first win of the season.
That's a tall order for New York's 26th-ranked run defense, and it's going to take a big game from a recent arrival in the Big Apple.
Middle linebacker Jon Beason, who the Giants acquired in a trade with the Carolina Panthers earlier this month, played well in his first start with Big Blue, racking up 12 stops in a loss to the Chicago Bears.
The 28-year-old was considered one of the NFL's top young linebackers not too long ago, but Beason lost most of the last two seasons to serious injuries.
If Beason is anywhere near old form, he could provide a badly needed boost for a reeling Giants defense.
We'll find out just how close Beason is to 100 percent Monday night against Peterson and the Vikings.