 Many multipurpose stadiums also had artificial turf playing surfaces, to ease the transition from baseball field to football field and vice versa.Most early installations of artificial turf such as the original AstroTurf was nothing more than carpet on top of concrete with little padding material that was easy to apply and remove.Such types of removable artificial turf caused frequent injuries to players, and eventually made free agents wary of signing with teams whose home field had artificial turf.