[Tristan Lall]

Although I'm not opposed to a structured implementation operated by the competition, I think it can be done differently, and with most of the (small) costs borne by the teams. As I proposed in that 2005 thread, an off-season event should try giving teams one instant replay coupon for the qualifying rounds and one for the elimination rounds, and then providing a brief window to present video for post-match review. This is practical and equitable.

A student alliance member would go to the challenge box and remit the coupons of all alliance members that showed up for the match (the whole alliance must agree it's replay-worthy), along with whatever video they want (cued to the crucial moment), within 1 min of the end of the match. The head referee will see the challenge is being made, and arrive to look at it (if the referee takes longer, then great, you have more time to cue the video). First, the referee decides if the video (as shown on the playback device) has enough information to show the situation at issue, then decides whether it changes the outcome, and finally, decides whether the evidence is sufficient that the video has not been tampered with or misrepresented.

If it fails the first test, the referee puts an end to it within moments. (For example, if there's not enough detail, or it doesn't show the right part of the field.) If it fails the second test, the team then knows it's not just the referee missing the call, but rather a deliberate decision to call it a particular way. (Rightly or wrongly, at that point it just becomes another futile challenge.) The third test may be a little more complicated—possibly requiring rewinding the video to hear the match being announced, or to verify that the right robots are on the field—but it's a straightforward test of credibility. (And because the burden of proof is on the team, and the timeline is tight, there's really no concern about the wrong video being reviewed, at least in the qualification round. In the elimination round, with the same teams playing, identification is more difficult, but at least the schedule isn't usually as constrained there.)

Why this? Because it strictly limits the number of reviews to minimize the aggregate delay, but still gives teams the opportunity to be heard. (Teams like it better when the officials hear them out, instead of ruling summarily.) It provides the referees with a procedural reason to change a bad call, without appearing indecisive, and gives the head referee a tool to better manage the rest of the referee crew (by understanding which calls are being blown). It also serves the teams notice that they share in the responsibility—if interested in challenging the officials' version of events, plan ahead to ensure that you're making video.

It's not perfect, but it doesn't have to be. I think you'd even see teams collaborating to supply post-match replay video to each other.