I found the transcript from Murray's match under the roof last year. Here it is:
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(Bolding mine)
Q. In what way are they different [the conditions under the roof]?
ANDY MURRAY: It’s very, very heavy and very humid. Sweating so much. I know it was hot outside today, but sweating a lot. And like from the start I noticed it very early.
Both of us were trying to get, well, white towels from the locker room because, you know, your hands were drenched. When I finished, it was like, you know, I’d been in a bath. It was very, very, very humid.
So it kind of slowed it down a lot, and I struggled to serve because it wasn’t coming off the strings that quickly.
Q. Did the court play differently?
ANDY MURRAY: Yeah, because of that, you know, it’s heavier. There was a lot more rallies in that match. I got very few free points from my serve when it did go in. Uhm, you know, can you really swing very hard at the ball and it can, you know, go in the net or it doesn’t really go anywhere. It’s very different.
Q. Were you surprised that you started the match under the roof, or did they consult with you?
ANDY MURRAY: Yeah, I was surprised because we’d asked, When are you gonna let us know if we’re gonna play under the roof or not? They said they would let us know as soon as the match was finished. And then, you know, it’s quite tough as well to judge.
It takes, I think, like 30 minutes to close the roof sorry, to open the roof, 20, 30 minutes to open it. To get the warmups and stuff right beforehand, you know, it was dry. We were warming up outside. It was dry. Was expecting to play without the roof, and then obviously it came.
I had never played, obviously, a grass court match, you know, indoors before, and it made a difference.
Q. Did you have a problem with the lights when the sunlight was still there as well?
ANDY MURRAY: No, I was asking the umpire, because I thought that they turned the lights up like from when we were warming up. The first couple of points, it seemed very bright in my first service game. I just asked them if they had. He said they hadn’t changed the lighting.
Yeah, it did seem pretty bright at the start. You know, obviously I was very happy to have finished.
Q. Is it fair to say then you would much rather play without the roof than with it closed?
ANDY MURRAY: Uhm, I like playing indoors. But it’s just when you haven’t practiced or ever played a match under a roof on grass, you don’t know what to expect. So now going in the next match, you know, I’ll know what to expect if the roof comes on.
But I still thought that for, you know, two and a half sets of the match I played great tennis. It’s just it took me a little while to get used to it.
Q. Did you think overall the conditions helped your game or hindered it?
ANDY MURRAY: Like I say, I don’t know. It’s just it took a while to get used to. Like I say, I played some great stuff tonight, and Stan played some great tennis as well. The only thing that I felt that was harder was to serve. I didn’t think that it was coming off the strings that quickly on the serve because of the humidity and it slowed the ball down.
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Well, one positive is that he knows what to expect now, but it seems like this may be a little more to Rafa's advantage. That said, there's a reason why they play these matches, so I'd say Murray's still has a very good chance.
