Back in October, Abby Wambach and a group of international soccer players filed a suit against FIFA and the Canadian Soccer Association claiming gender discrimination in their decision to play the 2015 Women's World Cup on artificial turf.
"It's a gender issue through and through," Wambach said, noting that the men's World Cup would never be played on artificial turf.
The lawsuit was subsequently dropped in January, but the topic remains on minds of the women preparing for the World Cup, which kicks off June 6.
In a recent interview with ESPN's Julie Foudy, Wambach stated, "There is no footballer on the planet that would prefer to play on artificial turf than natural grass."
Other than the greater perceived risk of injury, the game changes when played on an artificial surface. The ball moves quicker, long balls are more apt to roll out of bounds and the flow of the game is often interrupted.
Wambach also noted that the game is less physical as players are hesitant to slide on artificial turf.
How much of this supposed change in the game is perception and how much is reality?
To answer this question, we looked at every MLS game played on artificial turf over the past three years and compared them to games played on grass. During that time there were four teams -- Seattle Sounders, Portland Timbers, New England Revolution and Vancouver Whitecaps -- that played their home games on some variety of turf.
For this analysis, women's stats obviously would have been preferable to the MLS, but as Allison McCann of FiveThirtyEight.com notes, good women's sports data is severely lacking.
Based on the MLS data, the biggest differences between games played on turf and grass are the percentage of passes completed, particularly on long balls, and chances created in the game.
It makes inherent sense that a faster, turf field would make it harder to complete long passes. Teams that play a more direct, attacking style of play, like the United States and Canada, will be hurt most by the turf fields.
Japan, on the other hand, is known for its technical, possession style of play. In the 2011 World Cup, the Japanese had the highest possession percentage (57.2 percent) and most passes per game (647.5) of any team. Because many of their passes are short, they should conceivably be helped by the change in playing surfaces.
The MLS data also showed that there are more chances created and slightly more goals per game on grass surfaces than on turf. That could lead to a more defensive, less exciting product on the field in Canada.
Other minor differences that were found when comparing grass and turf fields include fewer clearances, intercepted passes and throw-ins on grass than on turf.
These results are not surprising; anyone who has played soccer on both surfaces knows that the ball moves faster on turf. What may be surprising, however, is that even professional soccer players in the MLS are affected by the change in surface. Although many of the differences are minor, the fact that they exist for all the stats outlined above is notable.
An increased risk of injury on turf was the other major complaint of the women filing the lawsuit. FIFA contends that there is no greater risk of injury on artificial turf than on grass. Other studies back this claim for major injuries like a torn ACL, but that does not solve the issue of turf burns and joint soreness.
As Michelle Akers tweets, there will be fewer sliding celebrations in Canada, but for the sake of the World Cup, let's hope the actual game is not impacted by FIFA's decision to play the tournament on turf.