Frank Mason III (0) and Landen Lucas of Kansas may have been disappointed when the Jayhawks lost to TCU in the Big 12 tournament, but their on to bigger and better things starting Friday in Tulsa. (Jamie Squire/Getty Images)

No. 1 Kansas left the Big 12 tournament early to merge onto Interstate 70 and return to Lawrence for an idle day, for some weekend practice and for a bunch of tape-watching — and you thought your weekend plans were blase. The 85-82 loss to TCU on Thursday means a decrease in buzz downtown, but otherwise means either something or nothing, which is true of just about everything in March.

Of the 17 national champions in the 2000s, nine won their conference tournaments. Eight did not. No national champion failed to reach at least its conference semifinals, so there’s that. Were Kansas to revel under the confetti in greater Phoenix four Monday nights from now, it could become the poster team for one-and-done conference-tournament showings.

Or maybe it couldn’t, because probably nobody would remember it lost in the Big 12 quarterfinals.

In a quiet losers’ locker room — quiet, but not funereal, this being a major conference tournament — Frank Mason III, who won player of the year in the Big 12 and might just win it in the whole land, looked ahead to the NCAA tournament. He still saw potential glory. “I think when we add another great piece to our team, Josh, once he comes back, he’ll be great for us,” he said.

He meant Josh Jackson, the 6-foot-8 freshman guard from Detroit whose absence owed to a suspension, which owed to backing a car into another car on Feb. 2 and then informing none of the key authorities, the key-est being Coach Bill Self. Without Jackson on Thursday, Kansas started to look bedraggled, its five starters each playing 35 minutes or more, and its three bench entries combining for 19 minutes and not so much else.

“We would be spent tomorrow,” Self said. “Tomorrow would have been a hard day for us.” To the inevitable question, then, of whether Thursday’s loss could be a boon for Kansas, Self said: “I don’t know. I’ll buy into it if that’s the only theory I know that will work for us.” That’s as good a March hypothesis as any.

The absence of Jackson for this particular game — “I knew it would be a hard game,” Self said — became a reference point as Kansas learned Sunday it earned a No. 1 seed and will face the winner of the North Carolina Central-UC Davis play-in game in the Midwest Region in its first NCAA tournament action on Friday in Tulsa. It enabled Self to say the loss “doesn’t mean anything is broken.” It enabled him to say with reason: “Today was a different deal. If you have another guy that plays 32 minutes it changes your whole depth situation.”

It even tempered one of the themes of the Kansas season, which is that the team seems to love climbing out of chasms. The TCU game marked the ninth time the Jayhawks (28-4) had faced a double-digit deficit, yet just the second loss. Second-most famously, they won at Kentucky on Jan. 29 after trailing by 12 in the first half. Most famously, they won against West Virginia on Feb. 14 after trailing by 14 with 2:58 left, a thing that will be remembered in Lawrence for at least the next 100 years or so.

Even while losing on Thursday, they trailed TCU by 11 with 13:57 left, yet led by four with two minutes left and with possession. That didn’t quite work out. Self spotted fatigue on TCU’s final possession, which began at 82-82 and featured Alex Robinson’s penetration and drift pass to the corner, Desmond Bane’s corner shot that led to Svi Mykhailiuk’s foul, and Bane’s three free throws.

In the great pinball machine of March, the Jayhawks have won the Big 12 tournament three times this decade and reached the Final Four in zero of those years. The Big 12 tournament champions in 2015 (Iowa State) and 2012 (Missouri) were gone from March after one game in the NCAA tournament, Iowa State falling to UAB as a No. 3 seed and Missouri to Norfolk State as a No. 2. The last Big 12 tournament champion to reach the Final Four was national champion Kansas in 2008. Before the Jayhawks’ Final Four appearance this decade (2012), they lost to Baylor in the Big 12 semifinals. On that night, Self said: “We’ve got to guard. We don’t guard. Let’s just call it like it is. We don’t guard.”

His desperately non-guarding team went to the national title game against Kentucky.

In entrenched reality, double-digit deficits, however suspenseful, are a bad habit for an event that rudely dispatches its entries after one loss. “Yeah, definitely,” Mason said. Asked if he feels any similarity when the deficits happen, he said, “I’m not really sure.”

That was the perfect March answer.

chuck.culpepper@washpost.com