Nike Flyknit Ultra FG

Soft Ground (SG) soleplates are specifically designed for use on wet and soft to very soft natural grass pitches that may also be muddy and/or waterlogged. Used worldwide, mainly during winter months, boots made for soft ground have removable, replaceable screw-in studs that can be plastic, entirely metal, or metal-tipped and typically come in a six-stud configuration – four at the forefoot, two slightly longer at the heel.

Artificial Grass surfaces, also known as all-weather surfaces, typically consist of 3G (rubber crumb) or 4G (longer pile, combination of rubber/sand infill, more closely resembling natural grass). Fifth generation artificial grass is yet to be widely used. Boots made for AG are specifically designed, typically using less nylon to increase durability for the extra abrasion associated with synthetic grass and featuring more numerous and densely concentrated studs. The studs may also vary in height for improved traction and/or be hollowed out to reduce weight and enhance cushioning. AG boots can also be used on firm ground (FG), though performance will depend on how dry and firm it is.

Turf, also known as AstroTurf, is an older, more unforgiving type of synthetic-grass surface consisting of either sand or water-based carpet typically laid on concrete. Subsequently a harder and faster surface, boots for use on turf (TF) usually have a cushioned midsole and a very durable, flat, multi-lugged or dimpled rubber outsole because turf requires light stud penetration. Owing to the hard nature of the surface and the friction it creates, no other outsole type should be used on turf as it will cause considerable wear to the studs and soleplate edges and may result in injury.

Indoor surfaces for small-sided games such as five-a-side and futsal are usually flat, extremely hard and unforgiving, and typically consist of varnished wood, linoleum, or a smooth, painted synthetic or composite material. For grip, indoor outsoles (IN) are usually flat to maximise ground contact and slick in appearance with a minimal, non-aggressive traction pattern or grooves for flex and to dissipate surface moisture. They typically use non-marking moulded gum rubber and often have midsole cushioning for shock absorption and comfort. Indoor shoes cannot be used on abrasive street surfaces such as concrete or gravel as they will quickly wear out.