Ahead of the 2021 season, Bank of America Stadium became the latest NFL venue to blanket its field with synthetic turf, in lieu of a natural grass surface, like the ones found at Soldier Field, Heinz Field, and Arrowhead Stadium.

To date, half of all NFL franchises now compete and/or practice on artificial turf, but if players had their way, every stadium would go organic. 

Last year, NFL Players Association president JC Tretter, a center for the Cleveland Browns, spoke out against the use of artificial turf, after a number of players suffered serious injuries in the early part of the 2020 season.

MetLife Stadium, in particular, became a focal point, when key members of the San Francisco 49ers were sidelined in games against the New York Jets and New York Giants, and noted the turf felt "sticky."

Data indicates the risk of non-contact lower-body injuries decreases on natural grass, but many teams across the league have found success (see: "The Greatest Show on Turf"), and stayed healthy, on the opposite type of playing field.

To coincide with our earlier research on "dome-field advantage," let's move to the ground level to explore differences in venues across the league.

Here we provide the full list of NFL stadiums by grass type and discuss the pros and cons to using natural grass versus synthetic turf.

The case for synthetic grass

In 1968, the Houston Oilers became the first pro football team to play on artificial turf, when the franchise relocated to the Astrodome, which had installed AstroTurf in 1966.

A number of NFL teams (the Eagles, Colts, Rams, and Patriots, to name a few) followed suit in transitioning from grass to artificial turf in the decades to come.

One reason the surface saw a boom in popularity was its cost-effectiveness.

With synthetic turf, far less maintenance is required throughout its lifespan, compared to natural grass, and it's arguably more environmentally friendly.

Pesticides, fertilizers, and constant watering are unnecessary, and the structure can withstand inclement weather, along with heavy foot traffic throughout the year.

Because of its durability, stadium owners find benefit in using turf to transform their sites into multipurpose venues that can host other profitable events, like concerts or tournaments, in addition to eight or nine home games in a 17-week NFL season.

Disadvantages of synthetic grass

Back in 2008, the NFLPA conducted a survey regarding the use of turf vs. natural grass and received substantial criticism of the former.

Nearly 93% of players believed artificial turf would shorten their careers, while 91% said the surface caused more soreness and fatigue.

As one player put it simply in the survey: "If a cow cannot eat it, we should not be playing on it."

Dirt and grass can break apart when force is applied, but turf doesn't possess the same pliability.

When an athlete's foot is stuck in the ground on turf, his or her leg is more likely to bend or break before the blade of artificial grass does.

Such was the case in 1993, when Chicago Bears receiver Wendell Davis ruptured both patella tendons on Philadelphia's treacherous turf field.

His injury became the catalyst for engineering highly advanced artificial surfaces, like FieldTurf, with softer fibers that sit atop sand and small rubber pellets, which offer more cushion to curtail the risk of injury.

Today's artificial turf, such as SoFi Stadium's Hellas Matrix Turf, is much safer than that of the 90s, but it has a long way to go to compete with natural grass, according to NFL players.

In Tretter's 2020 petition, he cited the league’s official injury reports from 2012-2018 as evidence that natural grass produces lower risk of injury.

According to the report, athletes have a 28% higher rate of non-contact lower extremity injuries on turf, while non-contact knee injuries occurred at a 32% higher rate and non-contact foot or ankle injuries happened at a 69% higher clip.

Tretter also argued that most of his teammates preferred to play on grass because their joints felt "noticeably stiffer" after playing on turf.

The case for natural grass

Tretter further pointed out that the Green Bay Packers and Pittsburgh Steelers cultivate natural grass fields, even though their stadiums exist in cold-weather climates.

Moreover, Arizona and Las Vegas inhabit indoor stadiums and eschew artificial turf.

The Cardinals' State Farm Stadium, in particular, has a retractable natural grass playing surface that can be removed for concerts, soccer matches, and college and high school games.

The technology and resources are available to provide players' their preferred playing field, it's just a matter of how much money owners are willing to spend on the endeavor.

Disadvantages of natural grass

The cost of maintenance can grow rather steep, especially when a stadium requires extra care to combat complicated weather.

Otherwise, you get a ghastly site like Soldier Field's worn-down grassland, or flying wedges of dirt, as was seen in a 2001 matchup at Ericsson Stadium (now Bank of America Stadium), home of the Carolina Panthers.

Even an exorbitant landscaping bill won't solve every issue that comes with natural grass. The Cardinals spent a pretty penny on their high-tech irrigation system but earned poor feedback from the visiting Detroit Lions, who complained the field was "awful" during a 2018 meeting.

The Packers have also shelled out a ton of money on Lambeau Field's heating system, which was introduced in 1967 to prevent the ground from freezing in the winter.

Nonetheless, natural grass makes players happy.

Even athletes in other sports have advocated for the surface, including soccer stars David Beckham and Abby Wambach.

But owners and GMs see the debate far differently and ultimately decide what's best for their franchises.

So for now, the NFL will remain perfectly divided, until one side can convince the other that the grass — real or artificial — is greener on the other side.