Hey there! I'm John Depa, the Executive Producer of the LEC!
Was lurking around Reddit and saw this post. I have experience with this— so I can definitely chime in! Ahaha.
I'll start with why things go wrong. Super TL;DR - A lot of reasons that are not related to the game, and it's getting better with time!
We've been talking about building an improved HUD since 2018. For a few years, we utilised a graphics system called Viz Trio (which we use for most of our other show graphics) to design and render our HUD over the game, but we found that it was ultimately too limiting for what we envisioned for a great HUD display for our game. And so, after awhile, we decided to simply build a new tool from the ground up to run our HUD. We test this tool regularly whenever we roll out new features, but ultimately, because we're building it ourselves, we don't benefit from the sheer amount of user testing that larger graphics systems benefit from. This is what ended up happening for VIT vs MAD last week, and the user who broke the system was actually me... I utilised the tool by setting a setting in an unanticipated way, and managed to crash it... (Sorry!)
Another common way things can go wrong relates to the methodology we use to get data from the live game. Our HUD relies on a new system that is still under active development. Sometimes things in this development change or react with the graphics system that we've built in unanticipated ways. We haven't had a crash like this in awhile, but if you had keen eyes, you may have spotted that when Fiddlesticks was hovered in Picks/Bans last week, the old splash art snuck back in due to an update in the API that we were calling to get his image.
At the end of 2022 our goal was to launch a 1:1 equal to our previous HUD and new HUD. Winter Split 2023 was spent adding new features (which resulted in some instability) that we nailed out and solidified into "HUD v2.0" that we've been running since the start of Spring. This push for stability was largely successful: so far in the Spring Split, only in this game that you mention we had to revert back to the "Old HUD" -- and it was because of my above-mentioned user error.
The two pieces of good news from that swap: (1) We've learned how to further Depa-proof the HUD settings to hopefully prevent me from breaking it in the same way again (thank gosh), and (2) we've identified a way to "recover" back into our New HUD following a swap away from it that we are now developing towards.
Overall, I think our new HUD brings with it a really huge benefit in all of the additional information that we're able to visualize with it. To name a few quick things, we've added Stacks for a select (and growing) number of Champions, Baron Buff Active Indicators (to show who's lost the buff without having to see them on the rift), lane-by-lane gold difference, XP bars, and to hit on some cosmetic upgrades, the Viego Transformation Indicator and dedicated icons for multi-kill events in the kill feed. (And we have a LOT more on our backlog and wish list, including entirely new HUD arrangements and views for specific moments of the game, which we're beta-ing behind the scenes as I type)
The benefits outweigh the potential risk of an occasional crash, and even when we do crash, we're still able to revert back to a safe "Old HUD" that still contains core information while we work to restore service.
I hope this provides some amount of transparency and cool info about what goes into the HUD! If you have other questions, you can AMAA! I'm here with Eike (Riot Timbolt) who has led the development of the HUD and is waaaay smarter than I am with regards to the technical stuff. Can't promise we can answer all of your questions, but we'll keep an eye out for replies!