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INDIANAPOLIS — Five months since the start of training camp, 13 games into the regular season, and Frank Reich’s offensive scheme is still a little hard to place in a box.

Reich’s Colts have won by riddling defenses with short, quick passes. By throwing it over the top, by pounding teams with the running game, by creating shots off of play-action, by ditching the huddle and pushing the pace out of the shotgun.

Indianapolis has poured points on defenses on days when its best playmaker has been the focal point, on days when he’s caught just one pass. On days when the tight ends are all healthy and making plays, on days when only two tight ends are available.

All of this is by design.

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Under Reich and offensive coordinator Nick Sirianni, this Colts offense is always going to be a little hard to place, always going to feel somewhat familiar and somehow on the cutting edge, all at the same time.

That’s exactly how Reich wants it.

“I don’t think there is a better compliment that we can receive than when a defensive coordinator, a person on the defensive staff that we know, comes up to us and says, ‘Man, you guys are hard to prepare for,’” Sirianni said.

Roots in Indianapolis

The roots of Reich’s offense should look familiar.

Especially here in Indianapolis.

This is where Reich got his coaching start in the NFL, where he spent six years moving up the ladder and making a name for himself, where the seeds of the offense he’s running now were first planted by two of the most iconic names in Colts history.

“I was in here with Tom Moore,” Reich said. “Really getting rooted, as far as the pass game was concerned, in what was happening here with Peyton, with Tom Moore, understanding how we attacked defenses in the passing game.”

The offense Peyton Manning made famous was brilliant in its simplicity.

A handful of plays called over and over, with a few adjustments off of those initial plays, a few more made possible by giving receivers “read” routes, routes that changed based on how the coverage was playing the receiver.

Reich fell in love with the blend of simplicity for his players and the difficulty of diagnosis for the defense.

“It’s just having multiple ways of attacking the defense,” Reich said. “We’re really running the same things over and over again, but to somebody watching from the outside, it doesn’t look like it. That way, what I find over the years, is players get good at what they do over and over again.”

Andrew Luck is making a lot of the same reads Manning once made. T.Y. Hilton is running a lot of the same routes Marvin Harrison took to the Hall of Fame.

Working with Manning and Moore taught Reich the veracity of an old axiom.

If it ain’t broke, don’t fix it.

“Don’t try to outsmart yourself,” Reich said. “You’ve got to always pull back on yourself as a coach to not try to get too fancy, not try to do too much. These plays have stood the test of time for a reason. There’s only so many ways you can stretch a defense horizontally or vertically. Let’s stick to those.”

History with no-huddle

Manning’s offense was a lot like the legendary K-Gun offense Reich ran as Jim Kelly’s backup in Buffalo during the Bills’ Super Bowl days.

No huddle. Pushing the tempo. A supremely talented quarterback calling plays at the line of scrimmage, a bevy of the game’s best playmakers at his disposal.

Reich spent his formative years in the NFL as a player and a coach in arguably the two best no-huddle offenses of all time. With all of that history, with all of that knowledge, it would have come as no surprise if Reich had walked into his offices in Indianapolis in February and promptly left any reference to the traditional huddle out on the curb on trash day. No need to recycle.

The no-huddle is even part of his history as a coordinator.

“When Nick and I were in San Diego, if you ever went back and watched all the tape … I don’t know what percentage it was, but I would say it was at least 70 percent of the offense was no-huddle,” Reich said.

But the no-huddle is not the defining feature of Reich’s offense in Indianapolis.

It is a part of his arsenal. When the Colts were struggling in Houston last week, still bogged down in the muck and mire of the Jacksonville loss the week before, Reich jump-started his offense by turning up the tempo.

“It’s a part of what we want to do, but that’s not the vision,” Reich said. “We know it’s a weapon, we know it’s an effective weapon, especially with the quarterback we have, (but) when you are not making first downs and you are struggling (in the no-huddle), there is a limit to what you can do. … We want to be more multiple than that.”

There’s that word again.

Multiple.

Reich’s offensive philosophy, boiled down to one word.

For all of the success he saw in the no-huddle in Buffalo and Indianapolis, Reich also saw limitations. Those K-gun offenses in Buffalo rarely changed their personnel. Manning’s offenses almost always had Harrison on the right, Reggie Wayne on the left, operating primarily out of two formations.

Reich wants to have options.

“When you go no-huddle, then T.Y. ends up in the same position all the time,” Reich said. “By not being exclusively no-huddle, we can move guys around in positions. We can put T.Y. where we want to, we can put (Eric) Ebron (in different spots), we can switch personnel groups. We can put offensive linemen in at tight end to throw deep play-action shots that we put in (or) to have an extra o-lineman in to do some stuff in the running game.”

Philosophically, Reich has grown beyond his roots.

“Believe me, I love the no-huddle, I have done the no-huddle for years as a player and as a coach,” Reich said. “We did it as well as anyone could do it. I just think it’s not ultimately the vision of who we are trying to be as an offense.”

'Cool plays of the week'

Multiplicity has become the cutting edge for NFL offenses.

For years, the NFL’s best offenses were schemes so recognizable that they carried monikers as recognizable as their quarterbacks, names like West Coast and Air Coryell and the Greatest Show on Turf.

Offensive identification is no longer quite that easy.

“Even the teams that I imagine are West Coast, maybe like a Kansas City, they’re definitely not (just) that,” Sirianni said. “They’re very innovative, they’re very creative, they’re multiple, they’re doing some stuff you see in the college ranks, and they’re doing the West Coast as well.”

Manning and Moore laid the foundation for Reich’s offense and he’s been adding to it ever since. Reich picked up a few things from Ken Whisenhunt during his season in Arizona, added a few of the Air Coryell-inspired plays Philip Rivers likes from his days working with Norv Turner during his three seasons in San Diego, added run-pass option plays, or RPOs, during his two years in Philadelphia with Doug Pederson.

Up front, Reich has pulled a few things from Chargers offensive line coach Joe D’Alessandris, who worked in Chan Gailey’s spread scheme in Kansas City and Buffalo; Sirianni has added some running-game intelligence from working with Anthony Lynn and offensive line coach Pat Meyer in the two seasons he spent with the Chargers while Reich was in Philadelphia.

A few wrinkles have even come from the college game. Tight ends coach Tom Manning brought a few ideas from the college game; wide receivers coach Kevin Patullo worked with renowned spread offense guru Noel Mazzone at Texas A&M last season.

“It’s an evolution of a lot of different offenses,” Sirianni said. “We try to keep it as systematic as possible within our system of words, but it has reached and pulled from different things to allow us to do what our team does best and what our players do the best.”

And it’s still evolving, sometimes on a week-to-week basis. Reich, Sirianni and the rest of the staff start by studying the opponent, making note of the concepts that have given the defense trouble. Teams who have quarterbacks similar to Luck — think the Saints with Drew Brees, Rivers in San Diego — get studied; Sean McVay’s widely respected Rams offense is always on the schedule.

Then there are the league-wide highlight reels. Each week, Colts staffers George Li and John Park make two cut-ups of plays from around the NFL: Every touchdown scored and a particular specialty Li simply calls “Cool Plays of the Week.”

“As you go through football, you take the best of what you see,” quarterbacks coach Marcus Brady said. “You see that play? OK, let’s take it apart, see how it works against the defense, because you don’t want to just take a play and run it, you’ve got to understand it, what gives it problems.”

All told, the Colts’ coaching staff absorbs a mountain of information.

That doesn’t mean Reich asks the players to climb the same mountain by handing them dozens of new plays each week.

Reich is constantly reminding himself not to do too much, not to outsmart himself.

“We’ll add new wrinkles and stuff, but we’ve been real basic, and we like to keep things simple," Colts running back Nyheim Hines said. "Our good plays are our good plays, no matter who we’re playing. We just try to do little wrinkles and show defenses new ways to get to it.”

Play calling

From all of that history, all of that film study, all of that editing and translating and installing, the coaching staff’s job is to boil it all down into a game plan for Sunday.

Reich’s role is to pick the right play at just the right time.

A few brilliant calls in each game are actually made earlier that week, targeted at a weakness the defense showed on film. A call like that is tailor-made; a coach knows it’s going to work the moment he sees the defense approach the line of scrimmage.

The hard part is knowing when to adapt.

“The (defense doesn't) always do exactly what you think they’re going to do,” Sirianni said. “The art of a play-caller — and Frank is one of the best, in my opinion — is to feel that, feel that, 'Here’s what we talked about the whole time, but I don’t have a good feeling.' Maybe it’s not going to be this play this time, because of what they’re doing or who they are or what their coordinator might have done against Frank five years ago.”

Boiled down to its essence, Reich values multiplicity because it means he always has an answer for what the defense is doing. That’s why he brought the RPOs over from Philadelphia; the multiplicity is built into the play itself, putting the defense in a position to choose its own method of destruction.

The Colts’ running game is designed the same way. From a philosophical standpoint, the running game is broken down into two categories: gap-oriented schemes, where the offensive line is trying to open a specific hole for the back, and zone scheme, where the back chooses the hole as it opens.

Indianapolis runs both.

“You can’t key in on what we’re doing,” Hines said. “Some weeks we think it’s going to be a gap-scheme game, and then we run zone the whole game. We hardly call any gap-scheme. Then the next week, they’re planning for zones and whams, and then that week we’ll pull guards and stuff. It keeps us a little bit ahead of the defense.”

* * *

Five months after the start of training camp, 13 games into the first year of this system, the Colts rank eighth in the NFL in total offense and scoring offense. Andrew Luck is turning in arguably the best season of his career. T.Y. Hilton is explosive. Eric Ebron has been a revelation. The offensive line looks better than it has since Manning was still taking snaps for the Colts.

But sometimes it’s best to look past the numbers, to apply Sirianni’s test, to go to the rest of the NFL and ask them to evaluate what it’s like to play Reich’s offense.

Dolphins coach Adam Gase: “You’ve got the whole history of his career involved in the offense, there’s probably some things he did as a player, there’s things that you see that when he was with Peyton, there’s things being at San Diego and then the Philly stuff. He’s just got a lot of different things that he can lean on. He can adjust during a game and get to certain things that can cause problems for our defense.”

Jaguars coach Doug Marrone: “If you defend this, and take this away, then hey, we’ve got to be careful, because this is what they’re doing the other way, and if you do things coverage-wise where you take (one thing) away, then they will be able to take advantage of us.”

Cowboys coach Jason Garrett: “A lot of different ways to run it and a lot of different ways to throw it. … The quarterback is really capable of doing anything, so there are no limitations there. They have a lot of weapons on offense that they use. They use them different ways. … So it’s multiple, it’s aggressive, it’s attacking and it’s a balanced offense. You have to be ready for a lot of different things.”

Exactly the way Reich wants it.