It was originally played 8v8 as well.

I'm not 100% sure, but I heard that the early versions (possibly the pre-order beta as well) of TF2 was 8v8 as well.

It's 8v8 on consoles.

IIRC cyzer was the early beta lead. He might have some more info about this.

It was primarily 6v6 in beta. I do know that a decent amount of teams toyed with 8v8, though. Animeman tried to settle it on Gotfrag by making a poll for 6v6, 7v7, and 8v8. 6v6 won by a fairly good margin.

I think what you're talking about the TF2 beta client which let a bunch of users beta test upcoming updates. I remember him having to do something with that. I could be wrong but I don't think he really played the game when it was actually in beta in 2007.

we reddit now

more useless TF history facts: TFC was played 9v9 (5 defense, 4 offense) in north american leagues (10v10 for the map canalzone). It wasn't uncommon to have an active roster of 15+ people. Comparing to the norm today that seems crazy...it was always interesting managing all of those personalities. The nice thing is you could actually have a 'full' scrimmage against your own team to try out your strats. You basically had a separate offensive team and a defensive team within your clan.

TF2: 6v6 pretty quickly won out as the competitive format of choice and the first tourney debuted 6v6. All of the jostling for format was basically hashed out in IRC by teams finding scrimmages prior to any league/tournament even being run...8v8 and 6v6 being the largest contingents. 6's gained momentum pretty quickly for finding scrims and the first competitive tourney was in that format (I seem to recall the decision being 'finalized' by a poll...I wanted 8v8 but it was clear 6v6 was going to win by that point...just harder to get 8v8 scrims and people were concerned about the whole LAN thing/sponsorships.) During the jostling time a lot of the initial class limits were also being worked out for competitive...I think initially the limit was just 2 per class and we quickly found out playing against 2 medics was less than fun...and vs 2 demomen likewise not fun.

Even though 6's won out there were 8v8 leagues that ran for probably the first 4-5 years of TF2? If not longer? I dunno I played in one of them for a while. It was definitely more casual, I'm sure most people still playing remember their existence better than I.

I think there were 8v8 leagues up until around 2011 but I may be wrong
edit: TWL?

this is also why if you sort your backpack by class, the order is scout, sniper, soldier, etc. instead of scout, soldier, pyro, etc.

twl had 5V5 FAST ATTACK, YEAAAH

UGC Highlander started around 2010, I believe.