Bluetracker

Tracks Blizzard employees across various accounts.

BlizzTravis has been killing it lately; his comment history is full of interesting and insightful information.

I clicked on /u/BlizzTravis after seeing a comment of his earlier, and was surprised by the number of comments over the past few months. I'm a pretty active user on this subreddit, but I had somehow missed a lot of them and wanted to highlight a few interesting ones here in case others missed them too (for example I didn't realize it was on the wish list to show MMR values, that maps always have exactly random chance of showing up, or that there was some desire to allow queuing with a preferred hero role).

Regarding the new MMR system and possible abuse:

The way the system functions, we aren't telling it what makes good play. It's simply measuring live games to determine what has proven effective for that particular situation.
So, to "game" the system, you have to win the game while executing in that situation in a way that players have already proven is how to play at a high proficiency level. Personally, I'd love to have games filled with folks playing like that. ;)
The assumption a lot of folks seemed to hop to is that there would be some singular stat that they could focus on to abuse things, which isn't true. Every stat we measure is used as part of the calculation for every situation. It's just a matter of weighting as some are more important than others for that situation. If you were to, say, focus solely on soaking XP with the assumption that its the most important stat, you'd likely be under-performing in other metrics that balances it out. If you aren't under-performing in other areas, but are soaking more XP than expected for that situation...you're actually playing better.

Win/loss is still the most important factor in MMR calculations:

You'll be getting MMR adjustments based on individual performance whether you win or lose. You still only gain MMR when you win and lose MMR when you lose, but if you're performing beyond expectations for your current MMR, you'll gain more MMR on a win and lose less on a loss. The net effect is that, over the course of multiple games, you'll more quickly arrive at the higher MMR that's indicative of your skill.
Then the opposite is also true if you're under-performing your current MMR.

Why the xp bonus for selecting random shows up so rarely:

We don't want to encourage people to select random normally, so the experience bonus only kicks in when the average queue time is above a particular threshold. The bonus is to then encourage people to play as a random so the system can more easily make matches and bring the queue time down.
Combine that with ongoing efforts to improve matchmaking which has led to lower queue times in general and you don't see the bonus pop up very much anymore.

Chance of getting a new map from the pool:

The system doesn't currently support weightings on maps. It's just a random selection. That's why, in the past, we temporarily reduced the map pool when a new map launches so it can show up more frequently.
That generates its own salt, though, so this time we just added it to the normal rotation instead.

How a player can place at 1k master after their ever ranked games:

To follow up on this, the placement was an interesting combination of things. First, you had a lot more games in QM than UD, but there was enough data in both QM and UD for the system to consider both valid choices to seed from. In that case, it uses UD as the seed since its more indicative of the play environment for ranked than QM is.
Interestingly, your QM MMR is significantly higher than your UD one. Your QM MMR is master tier. UD is diamond. Both are above the placement cap of Plat 3, though, so that ends up not mattering much. What did matter, though, is that your uncertainty in UD was still relatively high since you don't have a ton of games played there so, since that was used for the seed, your uncertainty coming into ranked was correspondingly high.
Then you won the first 6 games against high-skill teams, which bumped your MMR back up significantly due to the high uncertainty. Going 2 and 2 for the last 4 still left you with master tier MMR at the end of placements. It's not as high as your QM MMR, but a bit higher than your UD one.
There's nothing inherently wrong with placing into Master as long as you're a Master-tier player, so the question then becomes: are you actually a Master-tier player, as indicated by at least your QM performance, or is it a fluke of the system? As you continue to play ranked, it should become apparent which is the case.
Either way, this case was really useful to dig into and there are a few places along the flow that we may adjust things to improve the outcome in the future. Thanks for bringing it up!

Why they removed placement cap, and wants to show MMR value directly:

You have to be careful with anything that is artificially imposing limitations on where someone is ranked. Because rank is the only visible indicator of skill and people react allergically to folks of different ranks being in the same game together, even if they're the same skill, the matchmaking system prefers to match people of similar rank together. As long as their rank is appropriate to their MMR, that's a non-issue, but if they diverge too heavily, it causes problems.
That's part of why we got rid of the Diamond 3 cap. It worked fine at the start of a season when there were a lot of higher MMR folks at the cap, but as the season went on and the higher MMR players moved up to master, the system had a harder time making matches for people who were higher MMR, but joined later in the season so didn't have that large pool of other, similar players to be matched with.
The fix for this is making MMR visible, then decoupling MMR from rank entirely (and yes, that's on my wish list to do). At that point, we have a lot more freedom with rank without affecting matchmaking quality.

Would like to allow people to queue with preferred roles selected:

No, but I would like people to be able to queue up as a preferred role and use that as part of matchmaking. It wouldn't be hard enforced, but it would increase the likelihood that you'd have a mix of people willing to play the different roles on a matchmade draft team.

There are a lot of other good comments in there, these are just some that stood out to me. Thanks for being so interactive with the community /u/BlizzTravis.

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