Don’t watch much doubles? Here are some differences from singles.

Serena and Venus Williams will be competing in doubles Thursday night against Linda Noskova and Lucie Hradecka, both of the Czech Republic. The last time the Williams sisters played doubles together was in 2018 during the French Open, and there are quite a few differences between singles and doubles.

For starters, in doubles there are four people competing on court instead of two. The points tend to start with one player on each team standing at the net and the other player standing at the baseline. In doubles, the whole tennis court is in, so balls that float into the narrow alleys that extend from the baseline to the net on each side are no longer considered out of bounds.

The actual points in doubles tend to play out differently from singles too, with players hitting more crosscourt groundstrokes, volleys, swing volleys, lobs, and overheads. The placement of the serve is important too, with servers oftentimes aiming to hit the ball with a lot of spin either out wide or down the line.

Usually, the main goal of the player positioned at the baseline is to get to the net. So they will tend to return big and rally crosscourt until a ball floats just around the service line, then they’ll hit that ball and move to the net. That’s unless their partner who is positioned at the net interrupts the crosscourt rally with a volley — a strategy known as poaching.

While the players at the baseline largely want to keep the ball away from the person at the net by hitting the ball deep, they will sometimes test the net player by hitting the ball straight at them, or try to pass them by hitting the ball into the alley nearest them.

Hradecka played against Venus and Serena Williams at Wimbledon in 2012, but with a different partner, so she has an idea what she is up against, said Bethanie Mattek-Sands, a former world No. 1 doubles player who has competed against the Williams sisters.

Noskova “might not know quite what she’s getting into on Arthur Ashe but I think it will be an opportunity for the team to just feel that energy on the stadium for prime time,” Mattek-Sands said.

“I know they haven’t played in a little while but I feel like you can never count them out,” Mattek-Sands said of the Williams sisters. “They just have such a powerful game and I feel like as siblings you just know each other so well.”

Mattek-Sands said the main way to gauge how well the Williams sisters are playing is “by how they are serving and then putting the pressure on that second ball.”

“We know they can both hit big serves but how is their partner at the net handling that?” Matek-Sands asked. “And I think if they can put a lot of pressure on the returners, they’re going to be doing really well because they both return super big.”