The World Cup, concluding Sunday at the Meadowlands, has highlighted lessons for the National Football League regarding the use of instant replay technology. While soccer and American football differ significantly in style and rules, FIFA's implementation of the Video Assistant Referee (VAR) system offers insights into the benefits and pitfalls of video review.

FIFA introduced VAR at the 2018 tournament and expanded its use substantially during this summer’s World Cup, overturning over 100 calls. However, while VAR aimed to correct “clear and obvious errors” or serious missed incidents by referees, its practical application often fell short. Several decisions spanned several minutes and were controversial rather than straightforward, as seen in incidents such as a red card to Team USA’s Folarin Balogun and a disallowed goal involving Germany.

Mark Geiger, the first American to referee a World Cup knockout game, emphasized that the intent behind VAR was limited intervention to correct clear mistakes—not to fix every error or perfect officiating. This approach serves as an important guideline for the NFL as it expands its own replay review system.

Critics suggest several key lessons for football’s governing bodies. First, replay reviews should be swift. FIFA’s lengthy reviews, including a five-minute delay before Kylian Mbappé’s penalty kick and a seven-minute review determining a Senegal foul, disrupted the flow of matches. The NFL has accelerated its review process in recent years with better technology but is advised to keep decisions under 20–30 seconds to meet the standard of obvious errors.

Second, the number of replay reviews should be limited. FIFA’s unlimited review requests frequently stalled matches. Implementing a challenge system where coaches must balance the use of a finite number of challenges—as done in the NFL—could improve efficiency. Yet, the NFL has recently increased automatically reviewed plays and lessened the role of coaches in initiating reviews, potentially slowing the game.

Third, slow-motion footage should be used judiciously. Excessive frame-by-frame scrutiny can lead to decisions based on insignificant contact, such as minute touches of a player’s hair or marginal fouls unnoticed in real time. This tendency has caused controversy in the World Cup and threatens to complicate NFL reviews, especially with the introduction of “replay assist” for player-safety infractions.

Fourth, the NFL is cautioned against adopting a “sky judge” model, where officials off the field can impose calls missed on the field. FIFA’s experience shows that VAR has often overturned on-field officials’ judgments, raising questions about consistent officiating. The NFL has historically deferred to on-field referees and faced challenges when expanding replay to calls like pass interference. The increasing authority given to replay officials for player-safety-related calls may risk similar complications.

Finally, officials should avoid revisiting plays that preceded a scoring event or turnover by several seconds or yards. Egypt’s goal being overturned due to an earlier foul against Argentina sparked debate on the limits of replay. If a call was not made on the field, it may not meet the threshold of “clear and obvious” error, and the original result should stand.

Instant replay remains a vital tool for improving officiating, but its expanded use can introduce new controversies and disrupt game flow. As both FIFA and the NFL continue refining review protocols, a balance must be struck between technological assistance and preserving the human element inherent in fast-paced, dynamic sports.