Pokémon Sun and Moon’s online Battle Spot ladder is full of wild teams. Since all games are best-of-one (unlike live tournaments, which are best-of-three), many players bring gimmicks to steal the win in unexpected ways. Even the best competitive player can be caught off guard, because they never know what to expect.
Source: Kotaku – Pokémon Player Uses Explode On Veteran Competitor, Leaving Him Speechless