I’ve won a majority of my games queuing as Sigma 
3 wins, 1 draw and one loss for placements.
Only ones I didn’t win was a game where Symmetra was experiencing massive lag and the draw happened because Horizon Lunar Colony was so well defended and both our teams sucked on attack xD
If he’s as OP as people are initially saying, shouldn’t that easily offset being untrained with him? 
Can’t actually train a main tank outside comp… only mechanics, if you’re passed that…
maybe it’s just people haven’t got much experience fighting him. Almost as if he just came out?
What if I can play Sigma?
like from the PTR?
Then great, still, he should be locked out of competitive as would be usual for new heroes.
Wrecking Ball came into comp two weeks after he was released.
That was mid season as well.
Its beta dude, jesus, let people experiment. It’s not like this beta season sr matters.
I’ve played with bad Sigma players, we experimented, sometimes we lost, but we had fun and we weren’t screaming over sr like a bunch of brats.
Again it’s beta
There won’t be an MMR reset, this is going to carry over to Season 18 just as your MMR always has carried over.
I wasn’t thinking of playing Sigma in comp until I feel like I’ve mastered his kit. In the meantime I still have the other tanks to play.
I will say I’ve been surprised at how successful I’ve been faring with Brigitte. I had a game that was extremely fast paced, defending Horizon, and I was able to play sightlines in order to heal my team at the top of the stairs and our Widow across the balcony. Some very clutch Repair Pack tosses. She has never felt this exhilarating to play, and I like how much better she is at healing. Yes, her survivability is crap but I like myself a good challenge.
Sigma is a bit trickier to grasp at the moment, and I’ll put in as much practice as I can before I feel confident enough in using him. I only just now really started using Baptiste decently.
If you’re so worried about him don’t pick him then. Let others mmr “plummit” , it’s not against the rules to derank.
(if you’re playing in gold or below, then yea i believe a bad Sigma is annoying af, but it’s still the type of rank where you can climb out easly just by yourself, unlike high plat where you have to have a loss here and there)
I had around 10 mid-plat games yesterday. It seemed that whichever team had a sigma on them won the game because no-one really knows how to fight him.
I actually did my best on sigma in my last tanking placement, I was on Winston the other 4 games. We had an annoying pharah and none of the dps swapped to deal with her. I was on winston and other tank on orisa and we were getting wrecked by her. Swapping to Sigma and continuing to put a shield in her face nonstop even as she moved around actually helped us win the game because the game turned into a 6v5 pretty much.
When me and my mate strated playing we queued tank, and we couldn’t choose Sigma to our surprise. First 2 games haven’t seen Sigma, and then all of a sudden in the middle of a one match an enemy tank appears as Sigma, and the entire party is in shock and cofused XD (someone just got hit by a rock randomly and saw that shiled moving to his face and be liek “what is this?”)
We then realised he suddenly got unlocked to play on rq beta like after an hour it came live.
In later posts, he’s less confident that they won’t effect MMR.
I’m still confident that’s the case.
This is a beta after all. Gotta iron out the issues and rebalance some sections of the game
Well I suppose he’s playable because it’s the beta season and:
“Players can earn Competitive Points similar to other competitive mini seasons and qualify for Top 500 Leaderboards during the beta season. However, beta season stats will only be available for a limited time and will not count toward a player’s permanent Competitive Season stats.”
https://news.blizzard.com/en-us/overwatch/23060961/introducing-role-queue
In theory that means anything you do now doesn’t really matter as the only permanent thing should be the gold weapon points you get from playing.
It might also be affecting your MMR as off-seasons used to do but… can’t really know without an official statement.
And this is the problem.
The only thing you can practice outside of comp are basic mechanics.
Role Queue beta is at least better than regular comp, as it sounds like the stats from this season will neither be considered when RQ Beta ends nor saved on your profile.