Originally Posted by Fat ToF
Okay lets keep the hyperbole to a minimum here. Stall is not outclassed as a playstyle in tournaments so whoever said that is obviously mistaken. The biggest problem stall teams have is counterteaming, and that's a product of stall players typically being able to only use stall teams in the tier. On the ladder, stall teams are effective simply because a well-crafted team will win 80% of games without much thinking; it's a very easy ladder-cruising style. In tournaments, however, stall players can be at a disadvantage if their opponent knows what kind of team and style you run. Thus, it's more difficult to cruise with stall in tournaments, but if you're a good player and can mix-and-match styles, it limits counterteaming and makes stalling quite the possibility.
Stall teams will never be able to counter every single threat possible. On the ladder, you can prepare against the most commonly used things and that's why the 80% win percentage is feasible. You get randomly paired with someone and since the UU ladder isn't so great, large winning streaks aren't uncommon. In tournaments, you know who you're playing beforehand and the likelihood of seeing a unique Pokemon as an element of surprise is higher. On the ladder, not so much.
TL:DR: Stall is a good ladder playstyle, arguably the best for topping ladders and what-not, but in tournaments it's not cruise control and requires much more skill and creativity to use effectively.
I can't really agree with that last bit there, there can be little creativity for stall teams. All effective stall teams
are going to come out of a very limited pool of Pokemon in UU. At the conclusion of that RMT I try to tell why stall works, which it does, and its really because not of huge bulk anymore. If it was, you could be creative using whatever bulky Pokemon you could lay your hands on. This is not so, you have to rely on roles and lots of them. Offensive teams can be creative becaus all they want is a sweep, so they can use random sweepers like Venemoth which isn't UU but still works well. But when you look at trying to get as many roles filled up as you have to in UU you are going to have to resort on the old reliable, Umbreon over Audino for instance.
Stall allows little room for creativity because there are few creative walls that can still be effective.