how much of an effect on performance will a plus doubles ballpark rating have?

I especially looking at the +3 at sportsmens park and wondering whether it means that enough additional doubles happen to be worth using guys with better doubles ratings?  enough to matter?  even a good doubles hitter may have say 40 in a season.  If +3 means that a guy will hit 20% more doubles, thats adding 8.....?

do the extra doubles replace outs or do singles become doubles or how can I think about that effect?

thanks for any guidance

1.  Doubles teams are tough....I find it hard to win around guys who only hit doubles.   
2.  Twenty percent sounds a bit high, I would say closer to 10-15.....I am just guessing though.   I have seen guys get 70-80 doubles.
3.  The type of hit is determined after if it is a hit is determined.   In your case, I believe singles would become doubles.   

so does that mean that in a plus doubles park you want a lot of guys with high normalized singles numbers - so there are more hits that can move from a single to a double?  more so than getting guys with high normalized doubles ratings?

I would choose guys with higher normalized batting averages.

It doesn't really matter what type of hit it is ither than HR's.

If it is a homerun is done first so those hits won't be effected.


The bonus to doubles is the same (I think) for all players so, assuming two players have the same hit rate (minus home runs) the guy with a higher nomalized doubles number will get the bigger benefit.   

Does that make sense?

I won my 1st TOC with a high average doubles team in Fenway.  I had a ton of LH batters with a few switch hitters.  Don't remember who was all the team, but I do remember '94 Mike Kingery had a monster season.  If I were to do a doubles team again, I would go for high average, high doubles, low HR in league park II.  

Draft guys with a 7 2B/100AB normalized rating or higher and you should be fine.

I'm guessing you get maybe 25% more doubles at home. only half your games at home, your opponent is also getting more doubles, and doubles have only modest value 1 extra base so net value isn't all that high. when choosing between several players of similar value take the one with more doubles but I wouldn't give up too much to get more doubles.

What is the league you are joining?  If deadballers are allowed then going for doubles is probably a good idea. 

Yeah I am finding that at least in Fenway the doubles effect is there. I don't know yet about the other places, like Sportsmen's Park or Riverside. I have more or less doubles-oriented teams (though rounded Trentonjoe, with some real speed and high averages and a little HR power) playing in those parks just starting seasons now.
We will see how they work out, Trenton I hope you are not right about this, as this is supposed to be my adjustment to the low HR reality of the post-steroid, neo-deadball, post-modern, neo-ancient world we live in (see the movie "Agora" for an example of this world, and  for a sense of how the season finished for the "classics" team - worse than Boston and Atlanta last year, though the Joss Whedon "Serenity" world also works here, think that crew comes in second but make the playoffs as a wildcard). 

One very weird thing yesterday: I created this team called "Yankees fans for Fenway" which was actually an organization I wanted to start one time when they were talking of tearing down Fenway, which is one of the wonders of the modern world, and so I built a Fenway team - Gil Hodges, Mike Piazza, Willie Mays. Mays, by the way, hits a double a day in home games so far. But the weird thing is that Piazza hit a triple ! 

Now this is supposed to be a non-triples park: I purposely don't want to encourage the Vince Colemans of the world to hit triples. Piazza. Go figure. Also my right hand starting pitchers - Fergie Jenkins etc. are getting shelled, the couple of lefties in the bullpen are doing well- but after all one is Spaceman Bill Lee who always liked it there.

I use Fenway (a great doubles park) quite frequently.  If you draft guys with good batting average, plus AT LEAST a 7 2B/100AB# rating (preferrably an 8 or more), you will do quite well, assuming you also have good pitching.  Earl Webb, 00 Honus and a few others do great in doubles parks in OLs.