Joe Mahoney/Associated Press

The Kansas City Chiefs are all too familiar with two feelings under Andy Reid: building excitement when the stakes are low, and disappointment under the bright playoff lights.

That legacy of losing and failing to go beyond regular-season success reached a soul-shattering peak during yet another one-and-done playoff exit for the Chiefs under Reid, this time losing to the Tennessee Titans 22-21.

The Chiefs have now made the playoffs in four of Reid's five seasons as their head coach, which includes winning the AFC West each of the past two years. Their regular-season record is 53-27 under Reid, and in 2017, they were a resilient team, stringing together four- and five-game winning streaks and bouncing back from a midseason slump.

And yet nothing changed. There was no triumphant rise over a playoff hump or vanquishing of past demons. No, instead the Chiefs drift off into another winter of regret, and this time they'll be doing it after the team's heart has been put through a blender.

Heart-wrenching doesn't even begin to describe the latest Chiefs playoff thud, but it feels like a good place to start. The Titans were allowed back into a game that seemed destined to be a laughable blowout. In the second half, viewers at home should have been sent channel-flipping for more compelling entertainment.

Instead, a nation watched in disbelief, and a stadium watched in horror.

The Titans were lifeless at halftime, and through two quarters, the Chiefs dominated on every scoreboard, including the one that matters most.

Halftime offensive stats Team Points scored Yards gained First downs Chiefs 21 284 16 Titans 3 127 5 Source: NFL.com

The Titans didn't record a first down until the 44-second mark of the first quarter. And in just those opening 15 minutes, Chiefs quarterback Alex Smith threw for 154 yards.

Smith continued to do whatever he wanted throughout the first half against a Titans secondary that simply looked lost. He went into halftime averaging 10 yards per attempt with his deep accuracy on full display. The 33-year-old quarterback led a 79-yard touchdown drive with just 1:48 left in the half, which was the point when the Chiefs looked unbeatable.

In that moment, it seemed like everything would go according to script, with the heavy favorites holding an 18-point lead.

The Chiefs would stay hot after winning four straight games to end the season, and maybe rediscover their early-season form to threaten the New England Patriots in the AFC. The Titans would fold and finally have the excuse they needed to rid themselves of head coach Mike Mularkey. And Smith would keep rising to further complicate the Chiefs' quarterback decision going forward.

But that script didn't mention this:

Chiefs tight end Travis Kelce took a vicious shot to the head from Titans safety Johnathan Cyprien on that final drive in the second quarter. He could barely stand on his own at first and was then ruled out for the rest of the game.

It's a stinging uppercut to any team when an offensive weapon of Kelce's caliber leaves with over two full quarters left in a playoff game. At that point, Kelce, who finished the regular season with 83 receptions (first among tight ends) and 1,038 receiving yards (second), had already hauled in four catches for 66 yards and a touchdown.

But the loss of Kelce should have been a potential blow to worry about going forward into the divisional round. Against the Titans, his injury shouldn't have been crippling for two obvious reasons: the 18-point cushion, and the fact that wide receiver Tyreek Hill and running back Kareem Hunt were still two explosive, perfectly healthy options.

Kelce being sidelined isn't an acceptable excuse for the Chiefs offense gaining a mere six yards in the third quarter. Note the canyon separating this table from the one above.

Second-half offensive stats Team Points scored Yards gained First downs Chiefs 0 41 3 Titans 19 270 18 Source: NFL.com

The Chiefs held a three-score lead heading into the third quarter. Sure, that lead was trimmed to 11 points after the Titans offense woke from its slumber with a 91-yard touchdown drive. But driving nearly the entire field took over half of the third quarter.

So the Chiefs were still ahead by two scores when they took the field for their first possession of the second half. At that point, only 21:25 of game time remained, and they could still feel pretty comfortable with a double-digit lead.

The mashing of panic buttons wasn't necessary. A clock-killing drive or two was needed. Both Reid and offensive coordinator Matt Nagy should have been well aware of that fundamental football fact.

But in a decision that will be baffling all offseason, Hunt was given only five second-half carries.

That's the same Kareem Hunt who finished third in regular-season yards from scrimmage (1,782) and logged six games with 100-plus rushing yards. He needed to be given more of an opportunity to pound away and get the clock ticking, even if it was against the Titans' fourth-ranked run defense.

The Chiefs weren't able to generate anything offensively, leaving an exhausted defense on the field to get pancaked repeatedly by running back Derrick Henry. The massive human house finished with 156 rushing yards and 191 yards from scrimmage.

His night of inflicting both physical and emotional pain was highlighted by a 35-yard touchdown run on the second play of the fourth quarter. The play seemed to break the Chiefs' spirit while bringing Tennessee within five points.

The Chiefs bungled numerous opportunities to score insurance points, or at the very least keep drives alive and keep the clock moving.

The most haunting offseason memory will come from a drive that started on the Titans' 28-yard line after a muffed punt yet still ended in zero points when kicker Harrison Butker blasted his 48-yard attempt off the upright. A drop by tight end Orson Charles on 3rd-and-2 at midfield early in the fourth quarter also didn't help matters.

A third-down sack on the Chiefs' final drive hurt too, as it created a difficult 4th-and-9 situation. Even when they failed to convert that, the Chiefs still had hope. All they had to do was keep the rumbling Henry from gaining 10 yards on third down and Kansas City would get the ball back with likely about 1:40 remaining, trailing by one.

So of course the season ended the only way a Chiefs season can now: with a final dagger, and Henry's 22-yard run.

More than a season ended, too. A squandered opportunity came to a screeching halt, with sweeping changes looming.

The Chiefs are rightfully excited to begin the Patrick Mahomes experience in 2018. But as promising as the first-round pick might be, there are no certainties with a rookie quarterback. And the beginning of Mahomes' time as the starting man means the end of Smith, who is coming off a season when he was an MVP candidate after averaging eight yards per attempt. He also threw 26 touchdown passes with only five interceptions.

The offense in which Smith, Kelce, Hunt and Hill thrived could undergo an adjustment period too with Nagy, who took over play-calling duties midseason, set to possibly leave and pursue a head coaching opportunity. He has interviews with the Chicago Bears and Indianapolis Colts set up for Sunday, according to NFL Network's Ian Rapoport.

Veteran defensive pillars like outside linebacker Justin Houston and linebacker Derrick Johnson will also be a year older, and defensive tackle Bennie Logan could depart as a free agent.

The Chiefs still have a young offensive core, along with quality defensive pieces like cornerback Marcus Peters. They have the talent to shake a recent history of playoff flameouts.

For now, though, the letdowns and losing continue, and so does the postseason stench attached to Reid.