Spectator Assist is a really cool piece of tech written by S2PID a number of years ago intended to help people who watch Puyo Puyo videos identify chains in real time. It is, to my knowledge, the only visual aid ever created specifically to make the competitive Puyo experience easier to watch. But is SA the vaunted "killer tech" that transforms how Puyo is watched, or just a meaningless distraction?
First, a brief overview: Puyo Spectator Assist (PSA) is a Python program which reads video footage of a Puyo game as input, uses computer vision and machine learning techniques to identify what the possible trigger points and resultant chain lengths are on both players' boards, then creates an overlay with the information which can then be included in an OBS stream. Numbered reticles are placed over each trigger point, where the color of the reticle represents trigger color and the number indicates chain length. Two digit chain lengths are replaced with "?!" in order to build suspense during big chain battles.
One of the big successes of the overlay is how it packs a wealth of information into a compact form that integrates naturally with raw game footage. In fact, on a number of occasions players new to the English Puyo Community Discord have asked how to enable the reticles on their own copies of the game, only to discover it isn't a native feature. The "Chain Assist" feature added in the 2020 update to Puyo Puyo Champions seems to take inspiration from PSA as well.
The design of PSA was borne out of a common complaint from players new to watching competitive Puyo, which was that trying to figure out what was going on during gameplay was near impossible. Showing the trigger points helps map out possible game outcomes, and when a chain does get popped the final length of the chain is obvious.
Where I believe Spectator Assist falls short is the naivety of the chaining oracle; that is, it only recognizes salient chains that can be popped with just one more puyo. Oftentimes skilled players will either hold off on committing a chain until the very last moment, or temporarily de-commit a finished trigger in order to keep their options open and the opponent guessing. One of the most exciting parts of professional-level Puyo is the ability for players to magick out the perfect chain for the situation out of seemingly thin air, but PSA only offers a limited facsimile of the possibilities.
That being said, trying to pluck player intent out of the soup of a Puyo game board in real time is a losing proposition with currently available technology. Furthermore, the task of presenting the information from every possible potential future chain into a simple visual aid is a nigh impossible task. So, I can't exactly blame PSA for failing to live up to this standard given the state of the art.