INDIANAPOLIS, Ind. – And you thought the NFL was complicated with its pre-snap checks and audibles; defensive loops, twists and stunts; zone and press coverages; and on and on and on.

Sometimes, it’s best to dummy it down.

One of the fundamentals that has served Andrew Luck so well during his Comeback Tour?

“You throw the ball to the open guy,’’ he said Wednesday. “You try not to make it too complicated.’’

Quarterbacks operate in a chaotic environment. While they’re going through their progressions, angry men with bad intentions are bearing down.

“Things get a little stressful,’’ Luck admitted with a smile, “and you sit back, ‘Uh, just throw it to the open guy. Don’t overthink it. Keep it simple.’’’

And that’s been the beauty of Frank Reich’s offense through the first half of the season. It’s a system that, at its core, utilizes every available body on game day. It features multiple formations and a variety personnel groupings.

“We’re always looking to create a seed of doubt, keep people off balance,’’ he said.

It’s hard to imagine the scheme being more efficient, and that’s especially true over the past five games. During that stretch, the Luck-led offense has averaged 34 points and 436 yards per game. It’s converted 54.2 percent of its third-down situations and scored 16 touchdowns on 22 red-zone trips.

In keeping with the spread-it-around theme, those 16 red-zone TDs have been spread among nine different players.

Again, that’s a fundamental tenet of Reich’s offense: more is better. Keep in mind he was coordinator of a Philadelphia offense last season that pulled off a rarity. The Eagles were the first team since the 2003 New England Patriots to reach the Super Bowl without a 1,000-yard rusher OR a 1,000-yard receiver.

At the season’s midpoint, Luck has been adept at getting and keeping everyone – absolutely everyone – involved. A quick by-the-numbers look:

• 11. Players on the business end of at least one of Luck’s 23 touchdown passes. That already is a franchise record and tied for the third-most in NFL history. Atlanta’s Matt Ryan went to 13 different targets when he racked up his career-high 38 TDs in 2016. Tampa Bay’s Brad Johnson (2003) and New England’s Tom Brady (2005) delivered TDs to 12 players. When Peyton Manning tossed a then-league record 49 in ’04, they were spread among just six players.
•  15. Players with at least one reception. That’s the most since Luck involved 16 in 2012, his rookie season. The team record: 20 in 1987.
• 12 and 62. Tight ends have caught 12 TDs, most in the NFL, and 62 passes, second-most. In the 42-28 win at Oakland before the bye, three tight ends – Mo Alie-Cox, Eric Ebron and Jack Doyle – caught TDs in the same game for the first time in the league’s Super Bowl era.

The stabilization of the offensive line and emergence of the running game have been significant factors. Luck hasn’t been sacked the last three games, and has attempted a personal-best 156 passes without a sack, dating back to the Oct. 4 trip to New England. Marlon Mack has spearheaded a ground game that’s rushed for at least 220 yards in each of the last two games.

But there’s no overstating Luck’s expertise at executing Reich’s offense. He’s completing a career-best 65.8 percent of his passes, and that would be significantly higher had his receivers not endured a four-game stretch that included at least 18 drops.

Not surprisingly, he deflected the attention to his supporting cast.

“There’s a bunch of talented players here that go out there and work hard,’’ Luck said. “I trust all of the guys that are going out there on the field.

“We know if we want to be successful as a unit, that it takes everybody.’’

Moreover, at some point T.Y. Hilton is going to become more of a factor. During the offense’s prolific five-game stretch, he missed two games with a hamstring injury and contributed 9 catches, 174 yards and 2 TDs in the other three. Often, the four-time Pro Bowl selection has demanded double coverage, and that has opened up things for teammates.

Until he and Luck heat up, Hilton is biding his time.

“They’re doing a great job of keeping everybody involved, everybody going, and keeping the defense off balance,’’ he said. “We just want to keep defenses off balance, keep the defensive coordinators guessing.’’

As good as it’s been, Sunday figures to offer the offense’s stiffest test to date.

Jacksonville visits Lucas Oil Stadium and brings with it a defense that ranks among the NFL’s best: No. 2 in fewest total yards allowed (313.3), No. 1 in fewest passing yards (190) and No. 8 in scoring (16.75).

No one needs to be reminded how the Jaguars have dominated the recent series. They’ve won four of the last five meetings, and swept both games last year by a combined 57-10 score. Their 27-0 win at Lucas Oil Stadium marked the Colts’ first shutout loss since 1993 and featured 10 sacks of Jacoby Brissett.

“I think it starts with players, obviously,’’ Luck said of the Jaguars defense. “They have really good players all over. They’ve got guys who can cover, they’ve got really, really good linebackers, they’ve got a really stout, strong defensive line and they play the system really well.’’

You can follow Mike Chappell on Twitter at @mchappell51.