First wanna say I appreciate you talking about this and taking your time to explain. I think alot of us are fired up because the way Activision uses this in a way that hurts the community. But i wanted to ask why or what are the stats to prove the matchmaking helps? And how do you feel about the way Activision is using it? Because I have played cod since mw3 (original), and i have had so much fun up until about mw19 where my matches just felt sweatier and the game is less fun overall. I understand there is a need for a mmr system, I have been playing the Hunt Showdown 1896 that shows you your mmr and the mmr of the team overall. And I can tell you I would get smoked by people that are higher than me. Also not really a question but you made the comment about Xdefiant matchmaking, I think you are wrong about saying that's what caused it's downfall when in reality what really caused it to fall off was the lack of content and Ubisofts confusing mismanagement of the project. I think if it had the content and support it could've went head to head. Especially when everyone is very tired of the manipulation.
Most of the data is not shared publicly, but Activision published some of what they've looked at (Figure 3 on page 9 for example):
Call of Duty - Skill Whitepaper
I've run similar experiments and seen similar results across everything from in-game quit rates, to return rates (how often players come back within N days), new player retention rates, etc.
The particular problem with SBMM in COD is that above-average-skill players were acclimated to being above-average in most of their lobbies pre 2019. If you were a 75th percentile player by skill overall, in an average match with weak SBMM, you were also pretty close to 75th percentile in that match, give or take. So that ingrained expectations in veteran players. With tight SBMM now, a 75th percentile player is now much closer to the 50th percentile in their average match, which is less fun intrinsically. However, SBMM also increases the variance of outcomes, which means a 75th percentile player will see more highs than before (which is fun), but also more lows (which will feel bad because they were used to being consistently in the upper-middle).
What really adds insult to injury is that SBMM takes away KD as the objective measure of skill; it diminishes bragging rights. And more generally it dulls the sense of skill improvement. IMHO Activision didn't think about any of that from a design perspective (and still doesn't). Studios don't control the matchmaker, they just focus on the gameplay and content side, but are generally oblivious to the player matchmaking experience. SBMM improves the bottom line, that's why it's there, but there are so many ways it could be handled better (starting with transparency).
Regarding XDefiant, I would agree the game failed for many reasons, but with high certainty I would also say their executive decisions around matchmaking did not give the game the best chance to succeed (I don't mean that as hindsight; I gave a talk the week they launched last May saying the same thing), and with reasonable certainty I would say the lack of SBMM significantly accelerated the demise.
Mark Rubin assumed that random matchmaking would lead to more variety of outcomes for players ("sometimes you stomp; sometimes you get stomped"), when the exact opposite is true in reality. Random matchmaking leads to *less* variety of outcomes -- mathematically, provably -- which means the bottom half of players mostly just get stomped. The gameplay itself isn't that special, so rather than get stomped in a game they didn't even pay for, casuals will go off and play a different game. For the game to succeed, something about it would have to be so novel, interesting, and fun that players would be willing to get constantly stomped just for the rush of playing it (e.g. the good old days of COD4). Unless they can sustain a F2P with a small group of hardcore players, there was basically no chance for XDefiant to survive.
Ubisoft hasn't shared their data directly, but the console DAU charts I've seen show the worst retention of any comparable AAA launch, which is consistent with that theory. Lack of content didn't even have time to be a major factor, but I can see an argument for it contributing. At the very least, we can be sure that the lack of SBMM didn't *help* them retain players, even though it was probably great for marketing and player acquisition. It would be great to see their internal data though, especially the change in return rates between onboarding and gen pop.