Hey guys-

Is there a rough rule of thumb when comparing player performance in different ballparks?  I mean, if home park is -1 does it subtract 10 points off of OPS? 100? 

Just curious how you guys use it as a first glance.

I look at park factor primarily.  Here's what the help box says;

Ballpark - Each city option also has a unique ballpark. These are ballparks used by the big league team in this city. Minor league ballparks will be different at each level and may vary from world to world. Ballpark effects are ranked on a scale from - 4 to + 4, based on their impact on singles (1B), doubles (2B), triples (3B), homeruns to left field (HR LF) and homeruns to right field (HR RF). These values are based how the ballpark has historically performed in each of these respects as compared to its contemporary ballparks. A negative number indicates that the ballpark yields less than the average for the type of hit, while a positive indicates that the ballpark yields more than the average for the type of hit. The more negative or positive number, the more extreme the effect for that hit in that direction. These numbers are just indicators of the relative effect in the simulation engine. They are important for users and founded entirely on historical fact, but are meant for display purposes and not explicitly used in the simulation engine. 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. For all current real-life big league and most minor league cities, ballpark dimensions and effects are directly tied to their real counterparts. Choosing a ballpark can have a profound impact on the style and/or performance of your big league team. Capacity has no bearing on the game.

A point on a +/- rating used to mean between 5-10% in SLB, i've always assumed it means the same in HBD. Park factor is much more accurate for working out run suppression/promotion overall, but if you're trying to take advantage of a particular type of hit, they are still useful.

The only factor that effects batting average (and therefore OBP) is the singles factor. The others effect slugging percentage.

Posted by a_ersberg on 3/18/2012 9:59:00 AM (view original):
I look at park factor primarily.  Here's what the help box says;

Ballpark - Each city option also has a unique ballpark. These are ballparks used by the big league team in this city. Minor league ballparks will be different at each level and may vary from world to world. Ballpark effects are ranked on a scale from - 4 to + 4, based on their impact on singles (1B), doubles (2B), triples (3B), homeruns to left field (HR LF) and homeruns to right field (HR RF). These values are based how the ballpark has historically performed in each of these respects as compared to its contemporary ballparks. A negative number indicates that the ballpark yields less than the average for the type of hit, while a positive indicates that the ballpark yields more than the average for the type of hit. The more negative or positive number, the more extreme the effect for that hit in that direction. These numbers are just indicators of the relative effect in the simulation engine. They are important for users and founded entirely on historical fact, but are meant for display purposes and not explicitly used in the simulation engine. 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. For all current real-life big league and most minor league cities, ballpark dimensions and effects are directly tied to their real counterparts. Choosing a ballpark can have a profound impact on the style and/or performance of your big league team. Capacity has no bearing on the game.

The underlined and bolded sentence makes little sense to me.  It's important, but not explicitly used?  How would it be implicitly used?

They are important for users and founded entirely on historical fact, but are meant for display purposes and not explicitly used in the simulation engine. 

This is the sentence I was referring to.  It didn't "bold" or "underline" as I thought it would.