Recap
Artificial turf was first used in Major League Baseball in the Houston Astrodome in 1966, replacing the grass field used when the stadium opened a year earlier. The solution was to install a new type of artificial grass on the field, ChemGrass, which became known as AstroTurf.
Artificial turf was later installed in other stadiums such as Pittsburgh's Three Rivers Stadium, Philadelphia's Veterans Stadium, and Cincinnati's Riverfront Stadium. Early AstroTurf baseball fields used the traditional all-dirt path, but in the early 1970s, teams began using the "base cutout" layout on the diamond, with the only dirt being on the pitcher's mound, batter's circle, and in a "sliding box" around each base. With this layout, a painted arc would indicate where the edge of the outfield grass would normally be, to assist fielders in positioning themselves properly.
The biggest difference in play on artificial turf was that the ball bounced higher than on real grass, and also travelled faster, causing infielders to play farther back than they would normally, so that they would have sufficient time to react. The ball also had a truer bounce than on grass, so that on long throws fielders could deliberately bounce the ball in front of the player they were throwing to, with the certainty that it would travel in a straight line and not be deflected to the right or left. However, the biggest impact on the game of "turf", as it came to be called, was on the bodies of the players. The artificial surface, which was generally placed over a concrete base, had much less give to it than a traditional dirt and grass field did, which caused more wear-and-tear on knees, ankles, feet and the lower back, possibly even shortening the careers of those players who played a significant portion of their games on artificial surfaces.
In 2000, Tropicana Field became the first MLB field to use a softer artificial surface, FieldTurf. All other remaining artificial turf stadiums were either converted to FieldTurf or were replaced entirely by new natural grass stadiums. In just 13 years, between 1992 and 2005, the National League went from having half of its teams using artificial turf to all of them playing on natural grass. With the replacement of Minneapolis's Hubert H. Humphrey Metrodome by Target Field in 2010, only two MLB stadiums, both in the American League East, are still using artificial turf: Tropicana Field and Toronto's Rogers Centre, which converted to a next generation AstroTurf in 2010.
