When one thinks of Forretress, one word springs to mind: utility. Forretress's role in OU is defined by its use of the semi-exclusive Rapid Spin to clear entry hazards from the field. With Rapid Spin, it extends the longevity of a wide range of Pokemon such as Dragonite and Thundurus-T. The use of Rapid Spin also acts as a line of defense against teams that heavily rely on residual damage from entry hazards. In addition, Forretress occupies a unique niche among Rapid Spin users in that it has access to all three entry hazards. This makes Forretress flexible; it can allow your Pokemon to sweep or to stall. Perhaps what sets Forretress furthest apart from other spinners is its Steel typing and high Defense, making it one of the best Pokemon to tank the powerful Outrages and other physical moves thrown around in the OU tier.
Forretress is not without its severe disappointments. While it is the spinner that can fill the most roles on a team, it is also the easiest to spinblock. Forretress's lack of powerful offensive moves outside of Gyro Ball means OU's premier spinblockers—Jellicent and Sableye—will have no problem coming in and tanking (if you can even call it that) a hit to block Rapid Spin. While Forretress can do little back, Jellicent and Sableye will be more than happy to cripple it with Will-O-Wisp, while Gengar can wreck it with a powerful special move. The same lack of offensive presence means Forretress is setup bait for the numerous sweepers in OU. Thus, a solid plan for dealing with setup sweepers is necessary when running Forretress. Lastly, Forretress lacks any means of reliable recovery outside of Leftovers, so it is very prone to being worn down by the hazards it is designated to remove and the hits it is designated to tank. Altogether, Forretress's support can open many doors for your team, but without a solid plan for dealing with setup sweepers or spinblockers, your team itself might be opened.
Forretress's placement on a team should be for one reason alone: Rapid Spin. Without Rapid Spin, other Steel-types such as Ferrothorn and Skarmory are superior choices. Forretress's secondary function outside of Rapid Spinning is to tank hits, especially physical ones, for its teammates. With maximum Defense investment, Forretress becomes a handy tool to take the powerful Outrages thrown by Dragons and easily spins against opposing Pokemon that rely on weaker physical moves.
Rapid Spin with an accompanying hazard of choice will allow Forretress to support its teammates whether it is in the endeavor of sweeping or stalling. Spikes is the more exclusive of the two entry hazards listed and is more effective in wearing down the spinblockers Forretress has to combat. However, if your team is lacking a Stealth Rock user, Stealth Rock can be used instead of Spikes. Volt Switch is perhaps the best attacking move in Forretress's arsenal; not only can it be used to escape Magnezone, but it can also be used to act as a pivot for your team. Forretress is the slowest user of Volt Switch in the game, so it can effectively tank a hit for a teammate and switch out with Volt Switch to make sure your frailer, but more offensively inclined, Pokemon can come in safely. In the last slot, Forretress can run one move to prevent becoming setup bait for certain Pokemon. Forretress's low Speed and Steel typing makes Gyro Ball its most powerful move. On the other hand, Hidden Power Ice is more effective in taking on Gliscor, Landorus-T, and Dragon-types 4x weak to Ice. However, it is a very weak move and generally misses out on Terrakion, Kyurem-B and Tyranitar in terms of coverage.Team Options & Additional Comments >>>
Forretress can run a specially defensive spread in order to better sponge special attacks, particularly those from Dragon-types and Gengar. However, when considering that Forretress still takes over 50% from Latios's Specs Draco Meteor (non-choice special dragons often carry a move to cripple Forretress ) and that bulky Water-types can now burn Forretress with Scald, the niche that Specially Defensive Forretress had is now lost. Forretress can also run a multitude of different items effectively. Forretress can be used as a lead with Mental Herb to make it impossible to Taunt or OHKO; meanwhile, it can set up both Spikes and Stealth Rock while stopping opposing suicide leads with Rapid Spin. Red Card can be used with Sturdy to prevent Forretress from becoming setup bait, and it gives you the freedom to set up as many hazards as you want while the opponent uselessly sets up. Lastly, Shed Shell can be used to prevent either Magnezone or Gothitelle from trapping you. Note that with Volt Switch and proper prediction, Forretress can already prevent trapping from occurring.
Forretress can play around with either its hazards or attacking options and run a couple of other moves. Explosion can be used as a last ditch effort to prevent a Pokemon from setting up and to get a teammate in unscathed. However, the power nerf to Explosion this generation makes it an unappealing option. Toxic can be used to spread status and to cripple Sableye and Jellicent who might try to spinblock Forretress.
Checks and Counters
Jellicent, Sableye, and Gengar deserve a special place among Forretress counters because they block Rapid Spin, which is Forretress's primary purpose. It should be noted that Gengar will take hefty damage from Forretress's Gyro Ball if you predict the Gengar switch-in correctly. Heatran can come in on most of Forretress's moves and wipe it off the face of the earth with its Fire-type STAB. Other Fire-types such as Volcarona and Infernape can do the same. Gothitelle and Magnezone can trap Forretress and prey on its 4x Fire weakness to OHKO with HP Fire. Gothitelle can also Trick Forretress to lock it into a move where he is extremely easy to set up on. However, Forretress with Volt Switch have a chance to escape if the trappers do not immediately use HP Fire. Ferrothorn can come in on Forretress and proceed to set up hazards of its own, baiting Forretress to spin them. In the long run, Ferrothorn will beat Forretress one-on-one with a combination of Iron Barbs and Leech Seed should the Forretress not carry Pain Split. Donphan takes little from Hidden Power Ice or Gyro Ball and can spin away all of its hazards while slowly chipping at its health with Earthquake. Gliscor can set up a Swords Dance or Substitute on Forretress and eventually force it out with repeated Earthquakes if Forretress does not have Hidden Power Ice. It can also prevent hazard setup with the use of Taunt. Thundurus-T, Garchomp, Landorus, Jirachi, and Terrakion can all set up on Forretress quite easily if it lacks the proper moves to do significant damage to them. Lastly, with proper prediction, Xatu and Espeon can reflect the hazards Forretress sets up and hit back with a fatal Heat Wave or Hidden Power Fire.