Mo Alie-Cox was giddy as he put his hand in the turf for a fourth-and-one near midfield in the fourth quarter. 

He saw six Tampa Bay Buccaneers defensive linemen lined up in three-point stances, matching the Colts' six offensive linemen on the field. Flanking those linemen were linebacker Sir'Vocea Dennis and safety Ryan Neal. And creeping up toward the line of scrimmage were linebackers Devin White and K.J. Britt and cornerback Carlton Davis III. 

Alie-Cox knew it before the ball was even snapped.

We got 'em.  

"You're getting in your three-point stance, you're just like a kid in a candy store," Alie-Cox said. "You're so excited because you know it's going to work."

At the snap, White, Britt and Davis – just as the Colts expected – crashed toward the line of scrimmage, selling out to stop the run. Alie-Cox faked like he was going to block White, then dashed upfield. Quarterback Gardner Minshew II gave a little extra sell on the play fake to running back Jonathan Taylor, then floated the ball downfield to a wide-open Alie-Cox.

The play gained 30 yards, and the Colts turned the fourth down conversion into a Taylor touchdown a few plays later. Alie-Cox's reception proved critical in the Colts' 27-20 Week 12 win over the Buccaneers on Sunday at Lucas Oil Stadium. 

"You talk about it in a meeting but to actually see it unfold on the field and then actually completing it, you just see the excitement from everybody on the sideline and in the huddle," Alie-Cox said. "It was a critical point in the game, and kudos to coach for calling it."

Head coach Shane Steichen said tight ends coach Tom Manning proposed the play while the Colts' coaching staff was gameplanning for short-yardage situations last week. The Buccaneers had a specific look when in their goal line defense, and the Colts felt they could exploit that in a short-yardage situation further upfield. 

Steichen liked it. But the play required a fullback. So Steichen's follow-up question was: Who are we putting in there?

The Colts settled on an unconventional player: Linebacker Zaire Franklin. 

Steichen went to Franklin and told him he'd get his first career snap on offense if the play were called, with the directive to work inside out and set the edge for Minshew on the play-action pass. Franklin, jokingly, lobbied for the ball to be thrown his way. Maybe next time, Steichen laughed. 

But by putting Franklin on the field, the Colts went for a hard sell that they'd call a running play. Again: It worked. 

"Anything I can do to the help the team," Franklin said. "Shoutout to Shane for being creative, shoutout to the offense for helping me out.

"... Now I got a play in," Franklin added with a grin, "now I need targets."

The Colts didn't rep the play in practice, Alie-Cox said, just in a walkthrough setting. And it wasn't intended to be called near midfield – the thought was, if we have a short-yardage situation inside the Buccaneers' 30-yard line, we can call it then. Nobody flinched, though, when Steichen called the play at the Buccaneers' 49-yard line. 

Alie-Cox gained 30 yards – which would've been a touchdown had the play been called inside the 30. 

This was one of the Colts' three fourth down conversions – on four tries – on Sunday. A similarly well-designed and executed playcall generated a 24-yard completion to wide receiver Michael Pittman Jr. on fourth-and-one near midfield in the second quarter, with Minshew scrambling for a touchdown six plays later. The second conversion set up an end-of-half field goal try for Matt Gay, whose 58-yard kick missed off the left upright.

And the last conversion set the Colts up to take a 27-17 lead midway through the fourth quarter, proving critical in Sunday's win. 

Not only did those plays give the Colts a better chance to win, they boosted the trust Steichen has in his players to convert fourth downs in should-we-punt-or-not territory. 

"You have to earn that trust because if it doesn't go right, then everybody looks bad and then it falls back on him because he's the play caller," Pittman said. "You definitely have to earn that trust and we're just going to keep on building and building."

The pass to Alie-Cox, though, was one of those rare times where a team not only has the right playcall, but the right look for the playcall to be a virtual lock to work. Those maybe happen once or twice a game, if that. In this case, the Colts designed the right play for the look they got, and called it at the exact right time in the game to maximize its impact not only on Week 12, but on the AFC playoff picture. 

"We were just waiting for the right time to call it," Steichen said, "and it came up in a big-time situation. And we went for it and hit it."