Pokemon battles are difficult things to balance – many trainers simply don’t know how to make teams that would be considered “competitive.” There are many trainers who end up with teams that consist of too many pokemon that fill one criteria while ignoring the others. In a sense, making a competitive pokemon team is an art. You have to be very particular about which pokemon you’re willing to welcome onto your team; anticipating what role it would be successful in and where you’re willing to play it at. These roles include: sweeper, walls, tanks, and setup pokemon. Though there are other roles within these roles (types of sub-roles), these are the primary roles you need to fill.
Sweeper pokemon are pokemon meant to take out your enemies quickly. These pokemon can be either physical or special attackers (it may be wise to have both on your team) and have high speed stats. The idea here is to get the first hit in and to take out as many foes as you possibly can before having your sweeper faint. For a sweeper you should be EV training your pokemon in either special attack or physical attack as well as its speed stat. Also, this pokemon should have perfect IVs in its special attack or attack stat and its speed stat. Some pokemon that make good sweepers are, but are not limited to: Gengar, Dragonite, Weavile, Salamance, Bisharp, and Absol. There are many others, but those are just a few examples.
Walls are pokemon that should be able to take a hit. They can be physical or special walls and should have a defense stat to correspond to what kind of wall you want the pokemon to act as. A good strategy with wall pokemon is to use them as a stall. Most pokemon can learn toxic, so you can always poison an opponent while you have your wall out. Another good strategy is to have a recovery move on this pokemon as well. If this is the case, you can continuously heal as your opponent slowly dies of poison while being unable to make any massive hits on your pokemon at all. Some wall pokemon that you can use include: Blissey, Umbreon, Vaporeon, and Skarmory.
Tank pokemon are a mixture of decent defense, such as a wall, and attack like a sweeper. These pokemon are bulky and can be very powerful making them useful for not only competitive play, but for your in-game journey as well. Tanks should be able to stay in the battle for a decent amount of time and deal a good bit of damage. Also, it wouldn’t be a bad idea to add a healing move to this member of your team as well so that you can get the most out of it. Examples of tanks include: Starmie, Snorlax, Torkoal, and Metagross.
The idea of a setup pokemon is to turn the tides in your favor for the remainder of the battle. These pokemon can set up spikes, weather, or status effects. You can also uses this pokemon to set up your own team’s defenses with mist, magic coat, reflect, etc. It is a good idea to have a high speed on this pokemon so that your set up can actually happen in case your enemy throws out a sweeper. You can use a variety of pokemon as a setup pokemon. A good idea is to combine this role with another role – such as with your wall. Good pokemon for this role are Gliscor, Umbreon, Crobat, and Bronzong.
Now that you know the generalized roles that pokemon play in your competitive team, you are all set to find the balance that works best for you. Do you want to run a stalling team? Do you want to run a weather based team? It’s all up to you; and now that you know how to balance your team moderately, you’ll have a better time constructing your team.