Why do some players think the US Open courts and balls are slow -- and others call them fast?

"The court speed, I can't recall actually what was the year when it changed, when it started being slightly quicker than what it used to be,"

"But it's been pretty much the same speed for some years."

"I feel the balls are really soft, especially when it got cold. Obviously, when it gets cold, it's going to get slower, but even in the day, I mean, I feel like usually the balls get lighter and older now they feel really soft and heavy. It's just so frustrating. You're coming here expecting to be the same as every other year, and it's just not."

Players at the US Open offered conflicting assessments of court speed and ball performance, with some calling courts quicker and others saying they feel slower. Environmental factors such as temperature, wind and humidity can influence how balls and courts play, and organizers say balls and court surfaces remain unchanged from last year. The tournament uses Wilson balls, with a slightly heavier "extra duty" ball for the men's event. Several players described balls as softer or heavier when cold, while others said the courts have been consistent in speed over recent years.

Read at ESPN.com