Along with the size of the teams, the size of the field can vary considerably. In a park, or spring practice situation, a full-sized field may be available, but many games are played in the front and back yards of suburban and rural village neighborhoods, where the whole field may not be much more than ten to thirty yards long. In most of these situations, there are no yard lines, requiring some change in the definition of a first down. Instead of requiring that a team advance the ball ten yards, sometimes two pass completions result in a first down. Another option is to eliminate first downs entirely, so that a team gets four (sometimes five) chances to score; this process is most desirable on shorter fields.