If I'm playing in a stadium with a park factor of .900, and I want to estimate how well my players will do, can I simply multiply their performance by .9?

For example, if I are a free agent who hit .300 in a neutral stadium, can I assume he'll hit .270 (.300 x .9) in my stadium?
Of if I have a stadium with a 1.100 park factor, and I sign a pitcher with a 4.00 career ERA, can I expect him to pitch 4.40 for me?

Or does it not work like that?

Park factors, to my knowledge, have no affect on game play.  The 1B/2B/3B/LF/RF ratings do.  You know, the -1/0/-3/+2/+2.

I thought that the park factor was meant to be a summary of all of those individual effects, and I was hoping it would be a single number that would allow for quick estimates. Sounds like that's not the case?

Correct, that is not the case.

What the heck is it then?

From the HELP:

PF refers to the ballpark's park factor. This indicates the effect a ballpark has on offense as compared to its contemporary parks. A value of 1.00 means that the ballpark gives up exactly the league average number of runs over its history. Please note that this is not necessarily a measure of exactly how the ballparks will or even should perform in this Hardball Dynasty world. This is an indicator of how the ballpark performed against mostly different ballparks. For instance, Dodger Stadium historically gives up 87% of the average runs scored in a game. However, if all franchise owners had Dodger Stadium (or similar pitcher's parks), we would expect this stadium to give up the league average number of runs per game.

Thanks for sharing.

Where can this be found again?

When joining a world.
When you get to the screen where you choose your park.
The help tab at the top.

any other place? I'd like to use it for a blog segment, and don't want to have to pretend to join a world just for the Park Factors

Oh you just want to see the factors?

Check this thread.

scroll about halfway down for the complete list.

That's exactly what I was looking for but couldn't find it. Thanks.