An NFL player catches a pass. He fumbles. And then no one recovers because officials erroneously ruled the play incomplete.

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What happens next?

Well, as we learned Sunday at Soldier Field in Chicago, the NFL's 201-page rulebook covers that specific scenario. Case number 15.109 mandated that the incompletion call must stand, even though Chicago Bears receiver Anthony Miller's "catch" was clear and obvious, because there was no clear recovery.

That's not the only quirky twist in a rulebook that contains 82 pages of rules and then devotes another 119 pages to explaining how to apply them in specific situations. Some are more likely to occur than others. But as we prepare for the divisional round of the playoffs, let's explore five of the most interesting that could pop up at any time, not unlike what we just witnessed in Chicago.

We'll plug in hypothetical team names and players to make it easier for everyone to understand.

1. No intentional grounding even if there is intentional grounding

Scenario: The ball is at the New York Jets' 37-yard line. New England Patriots quarterback Tom Brady, under pressure in the pocket at the 44, throws toward the sideline. The line judge marks the ball at the 45, making it a backward pass and a loss of 8 yards. But replays show that the ball actually went out of bounds at the 43, and there was no eligible receiver in the area. The Patriots challenge the spot, hoping it would be ruled a forward pass to reverse the yard loss and keep them in field goal range -- knowing there was no downside for an intentional grounding call.

Result: The call is changed to an incomplete pass, returning the line of scrimmage to the Jets' 37.

Explanation: The Jets get jobbed. Although the replay showed an incomplete pass, it also made clear that intentional grounding should have been called. But NFL rules prohibit replay from creating a foul for intentional grounding in this scenario, which in this case the Patriots knew before challenging (you know Bill Belichick knows that rule!). Replay can examine all reviewable aspects of a play, even if it isn't the designated reason for the challenge, but intentional grounding isn't reviewable. It could be called in this situation only if, according to A.R. 15.137 in the NFL rulebook, "officials had thrown a flag initially for intentional grounding and then picked it up because of the line judge's ruling ... or if the referee had made an announcement regarding grounding before the review."

2. Why a clear recovery is so important

Scenario: Officials rule that Los Angeles Chargers tailback Melvin Gordon has scored on a 9-yard touchdown run against the Kansas City Chiefs. All scoring plays are reviewed, and replay shows Gordon fumbled just before he reached the goal line.

Result: The Chiefs would be awarded the ball if they made a clear recovery. But if there were no clear recovery -- a likely scenario given the officials' immediate touchdown signal -- the ball would be returned to the Chargers at the spot of the fumble, per A.R. 15.164. (Unless it was fourth down and the ball was fumbled short of the line to gain, in which case the Chiefs would take over at the spot of the fumble.)

Explanation: This is a fundamentally different outcome from what we saw at Soldier Field, where the lack of a clear recovery required the ruling on the field (an incomplete pass) to stand. Had the same standard applied here, Gordon and the Chargers would have been credited with a touchdown. Instead, the Chargers retain possession of the ball, spotted where Gordon lost it, to account for a fumble that wasn't recovered.

3. Two legs don't equal one hand

Scenario: Green Bay Packers tailback Aaron Jones fumbles at the Minnesota Vikings' 30-yard line. During the scramble for the ball, Vikings cornerback Xavier Rhodes ends up on the ground. With players piling on top of him, Rhodes can't grab the ball with his hands. Instead, it is squeezed between his knees. Packers receiver Davante Adams approaches. While still standing, Adams snatches the ball from Rhodes' knees and runs into the end zone.

Ruling: The Packers are awarded a touchdown.

Explanation: Possession requires control with the hands or arms, according to A.R. 3.5 in the rulebook. Rhodes thus didn't have possession, and Adams wasn't down by contact when he ripped the ball away.

4. Manipulating the start of sudden death

Scenario: On the opening possession of overtime, Pittsburgh Steelers quarterback Ben Roethlisberger throws an interception to Baltimore Ravens cornerback Jimmy Smith. But then Smith fumbles during the return, and Steelers receiver Antonio Brown recovers. Meanwhile, Ravens linebacker Terrell Suggs is called for roughing the passer.

Result: The Steelers decline the penalty and the game moves into sudden death.

Explanation: NFL overtime requires both teams to have a possession before sudden death begins, unless a touchdown is scored on the first possession. Smith's interception, and subsequent fumble, would actually count for the Ravens' possession. That would allow the Steelers to win on a field goal during the continuation of their first possession. The roughing penalty would have added 15 yards and put the Steelers close to field goal range, but it also would officially negate the play. So accepting the penalty would allow the Ravens a possession if the Steelers settled for a field goal. According to A.R. 16.20 in the rulebook, the Steelers' best decision would be to decline the penalty, take possession where Brown recovered and put themselves in position to win with a field goal before the Ravens' offense ever even got on the field.

5. Winning with an illegal tackle

Scenario: Another overtime possession manipulation! The Steelers kick a field goal on the first possession of overtime. On the first play of the next possession, Ravens quarterback Lamar Jackson throws an interception to Steelers cornerback Joe Haden. During the return, Haden fumbles. Ravens tight end Maxx Williams recovers and begins running toward the end zone. He gets to the 5-yard line before Steelers safety Morgan Burnett tackles him by the collar, drawing a horse-collar penalty.

Result: Per A.R. 16.25, the game is over and the Steelers win, despite taking a penalty.

Explanation: Technically, both teams have had possessions by this point. The Ravens failed to score on their first possession, which ended with the Haden interception. If Williams scored, the Ravens would have won. (That ruling was inserted into the rulebook in 2018.) But because he did not, and the Ravens had their fair opportunity, the rules require officials to disregard the horse-collar penalty and end the game. In that situation, players can make illegal tackles -- by the face mask and/or collar, and also by being tripped -- with impunity to make a game-winning play.