DENVER -- The events of Nov. 15, 2015, at Denver's Mile High Stadium felt at the time like temporary relief for the Kansas City Chiefs. They ended years of frustration by finally breaking through against their longtime tormentors and AFC West bullies, the Denver Broncos.
The Chiefs ended a seven-game game losing streak against the Broncos that day with a 29-13 victory. For added measure, they intercepted Peyton Manning four times before he was pulled from the game in what would be the future Hall of Fame quarterback's last game against the Chiefs.
The feeling of beating the Broncos looked to be fleeting. The Chiefs, despite the victory, watched as the Broncos eventually claimed a fifth straight AFC West championship and the franchise's third Super Bowl victory.
But that day's developments remain significant. They served as a turning point for the Chiefs and the AFC West as a whole.
The Chiefs haven't lost to the Broncos since, their winning streak against Denver at five games heading into Monday night's matchup between the teams. The two division titles since 2015 belong to the Chiefs, and as the only 3-0 team in the AFC West, a third straight championship already appears theirs to lose.
A few factors play into this, including Manning's retirement after that 2015 season. The biggest reason is the plan Kansas City set in motion in 2013 when Andy Reid was hired as the Chiefs' head coach.
It took a couple of seasons for the team to see significant results, but eventually Kansas City has come to not only rule over the Broncos but also the other division rivals, the Chargers and Raiders. The Chiefs have won 17 of 18 games against AFC West teams by building an offense the others haven't been able to keep pace with.
"Look what they've done and look how they can win games now in particular, how balanced they've become on offense, how multifaceted they've become on offense," said ESPN front-office insider Louis Riddick, who once worked with Reid as a scout with the Philadelphia Eagles. "They can truly play the kind of football that Andy wants to play, the kind he's always wanted to play. He would like to throw the football, get a big lead on you and then grind you down with the running game and then on defense that allows them to kind of play one-dimensional, meaning they can just rush the passer.
"He's built a multidimensional team, particularly on offense, to where he has so many options that maybe he didn't have when he first got there. His area of expertise being the offense, he's built it into a juggernaut in terms of how they can play, and I think that's what's making the difference in Kansas City. It's worked perfectly. They can play so many different styles. They have quick-strike ability. They have grind-it-out running ability. They have control-the-field ability. So he can just kind of do what he needs to do in order to win a game. They're in a very good spot right now, at least on that side of the ball."
The Chiefs haven't yet translated all of this to great success outside the AFC West. They went 17-13 over the past three years in regular-season games against opponents from outside the division and 1-3 in the playoffs.
But they've done many good things in the AFC West and particularly against the Broncos. The Chiefs have at least 27 points in each of their five straight wins against Denver. They had 27 or more only once in the previous 10 games against the Broncos.
Reid shrugged off the Chiefs' recent success against the Broncos and said he paid little attention to the reasons control of the division has flipped from Denver to Kansas City.
"When you're in the mix, you don't have time to evaluate all of that," he said.
Chiefs offensive tackle Mitchell Schwartz said he detected a slightly different atmosphere in the locker room the week of his first game against Denver in 2016. The Chiefs were one game into their winning streak against the Broncos, but Denver was still the defending Super Bowl champion.
"You could feel it," said Schwartz, who played for the Browns his first four NFL seasons. "A lot of it was because they were such a good team and they had been so successful. We knew we had to bring it against a tough defense."
The Chiefs made the playoffs in two of the first three seasons after Reid's arrival, in 2013 and 2015. But they were wild-card entrants each time.
They needed to be better in division games if they were going to win the AFC West. They were 10-8 against AFC West opponents in 2013, 2014 and 2015.
"The first order of business is to try to win your division, and to do that you will try to build your team with an eye towards [division rivals]," Riddick said. "[Reid] had an eye on what Denver had, especially on the defensive side of the ball."
The Broncos in 2015 had a great defense that included the so-called "No Fly Zone" with Pro Bowl cornerbacks Chris Harris and Aqib Talib. The Broncos also had a premier pass-rusher in Von Miller, who, like other top AFC West pass-rushers Khalil Mack of Oakland and Melvin Ingram of the Chargers, frequently lined up on the left side.
To win against Denver's secondary, the Chiefs overhauled their wide receiving group. Their top four wide receivers, including starters Tyreek Hill and Sammy Watkins, have arrived since 2016. This year they replaced longtime quarterback Alex Smith with Patrick Mahomes, who has 13 touchdowns and zero interceptions in the first three games.
To counter Miller, the Chiefs in 2016 made the wise and underrated move to sign a top right tackle, Schwartz. He has been everything the Chiefs hoped for in bolstering their protection.
"There's no doubt that knowing what the AFC West was giving [Reid] in terms of matchup problems, he needed to make sure the right tackle situation was solidified," Riddick said.
Miller had three sacks in his first game against the Chiefs and Schwartz but none in the three games since.
Said Reid of Schwartz vs. Miller: "It's a fun matchup to watch. They get after each other."
Monday night's game feels like a last chance to keep the Chiefs from running away with another division title. A victory against the Broncos would give the Chiefs a lead of at least two games over each of the other AFC West teams. They would be 2-0 in division games, with two road wins.
That lead wouldn't be insurmountable, but the Chiefs might be difficult to catch, something their rivals are getting used to.
And something they could keep seeing.
The defense needs plenty of work, but the Chiefs this season have been able to overcome that.
"They're still young," Riddick said. "Look down their lineup. These are guys you can see playing for them for the next three, four, five years. Patrick's not going anywhere. Kareem's not going anywhere. Ty's not going anywhere. Sammy was just signed to a big-time contract. Travis is not going anywhere. The offensive line, Demarcus Robinson, they're not going anywhere. They're built for the now and for the future, which is kind of scary from a competitor's standpoint.
"They have the right plan in place. They have the right coach in place. They have the right coach-GM relationship in place. And they have the franchise quarterback with ridiculous weapons. Now they have to take care of the defensive side of the ball. But as long as there's nothing unforeseeable that comes in and destroys the kind of chemistry and the kind of plan they have going, there's no reason they shouldn't be considered AFC West favorites every year for the next three or four years."
The Chiefs can look back at their 2015 breakthrough against the Broncos as the moment when it all started. The Chiefs went to Denver with a 2-5 record, making a victory over the eventual Super Bowl champions look unlikely.
But their time had finally come, and beating the Broncos can't be overlooked in explaining everything that has followed.
"For sure that game was big," Riddick said. "Division games always mean more, emotionally and psychologically. So when you beat a team like that that's had your number, yeah, it means a ton."