For the past two years, I've tried to shed some light on the world of NFL officiating through a penalty database provided by ESPN Stats & Information. Now, it's time to expand our look into specific calls that often carry the postgame discussion on Monday and Tuesday.

My goal isn't simply to criticize officials for poor calls or praise them for good ones, but to expose the gray area involved -- both in the individual decisions and the entire exercise of officiating at large. Feel free to tweet play nominations or other suggestions my way at @SeifertESPN. In this inaugural attempt, I'll shut it down after a round number of three.

(@SethSimonson suggested culling everything from the active night of referee Jerome Boger in the New England Patriots' 43-17 victory over the Cincinnati Bengals, but I'll branch out a bit more than that.)

Play: Unnecessary roughness penalty on New York Jets linebacker Quinton Coples

Referee crew: Ronald Torbert

Analysis: Two different plays occur when reviewing this instance: one in live view and another in replay. Initially, it appeared that Coples -- after reaching the San Diego Chargers' backfield unblocked -- knocked down running back Ronald Brown with an arm to the chest, a legal play. Upon review, however, it's clear that Coples' left biceps struck the left side of Brown's helmet and part of his face mask as well.

The force not only upended Brown for a 2-yard loss, but it also dislodged his helmet and caused a concussion.

The NFL doesn't specifically outlaw "clothesline" tackles in its rule book. Officials inconsistently call it, but in this case, Coples' contact to Brown's helmet seemed a fair penalty prompt. Rule 12, Section 2, Article 12(c) states: "All players are prohibited from striking, swinging at or clubbing the head, neck or face of an opponent with the wrist(s), arm(s), elbow(s) or hand(s)."

Calais Campbell suffered an MCL injury when he was chop-blocked by Broncos tight end Julius Thomas. AP Photo/Joe Mahoney

Play: Unnecessary roughness penalty, blindside block, on Patriots defensive lineman Dominique Easley.

Referee crew: Boger

Analysis: The block occurred during a nebulous moment; officials were late to blow the whistle after an incomplete pass to Bengals receiver A.J. Green. In the live view, it appeared Green might have caught the pass and fumbled, prompting safety Patrick Chung to scoop the ball and begin returning. (The back judge threw a bean bag, seemingly noting a change of possession.)

As the whistles blew, Easley approached Bengals running back Gio Bernard and knocked him down with a forceful block on the back of the left shoulder. Boger penalized Easley 15 yards for the hit, stating: "After the play was over, unnecessary roughness with a blindside block."

Rule 12, Section 2, Article 7 (8) states that a "defenseless player" is a one who receives a 'blindside' block when the path of the offensive blocker is toward or parallel to his own end line, and he approaches the opponent from behind or from the side."

Another complicating factor was that, technically, the block came after the play was over. Chung's apparent return was not live. The play ended when the ball fell from Green's hands. The rule book doesn't explicitly state that such penalties are limited to "live" occasions, but it stands to reason that a block can't happen when there is no return. Former NFL officiating supervisor Mike Pereira was among those who put forth that argument.

Play: Chop-block penalty on Denver Broncos tight end Julius Thomas

Referee crew: Bill Leavy

Analysis: Generally speaking, a chop-block occurs when one player hits a defender low and the other hits him high. In this case, Thomas cut-blocked Arizona Cardinals defensive end Calais Campbell with contact to his right leg, causing Campbell to suffer an MCL injury. Cardinals coach Bruce Arians declared it the dirtiest play he had seen in 37 years.

It's not entirely clear, however, whether the play was even illegal, much less dirty. (Update: The NFL confirmed Monday that it was an illegal chop block.) The player who ostensibly blocked Campbell high was left tackle Ryan Clady, whose only contact with Campbell came as Campbell fell into him. One interpretation suggests this was still an illegal "lure block," described in an example within Rule 12, Section 2, Article 3 of the rule book: "A1 [Thomas] chops a defensive player while A2 [Clady] confronts the defensive player in a pass-blocking posture but is not physically engaged with the defensive player."

Did Clady "confront" Campbell? It's true that he faced Campbell in a pass-blocking stance. Did Campbell turn away from Thomas to focus on beating Clady? This is the gray area where so many officiating decisions lie. In the NFL, a "confrontation" can occur without physical contact. If this play doesn't reflect the intent of the "lure block" rule, I would like to know what does.