Ballpark Singles

I understand the concept of homeruns being easier in some parks and easier for a particular type of hitter. But, does it make sense to say that a ballpark is singles friendly for one type of hitter? Is the left side of the infield artificial turf in DC Stadium and the right side grass? Of course not.

So, I'm guessing that ballpark singles (>) are just a mechanism for increasing the accuracy of simulating batting averages and E.R.A's and has little to do with a cause and effect relationship between the stadium infield and any other factor.

I'm also guessing clutch hitting symbols ($) are another way to gain additional statistical accuracy and has nothing to do with measuring whether a particular hitter is clutch.

In other words, if Cap Peterson is expected to hit .251 and plays half of his games in D.C. Stadium then clutch hitting and ballpark singles are just additional mechanisms for increasing the probability that Cap Peterson will bat .251 over a 162 game season against league foes and has nothing to do with measuring if he's clutch or if the left-hand side of the stadium infield is singles friendly.

They could have just as easily have had symbols measuring how Cap Peterson hits on Tuesdays and Thursdays as opposed to other days of the week and incorporated that into the player card with special symbols and it would accomplish the same objective. At least, that's my perception.

fact: Fenway park increases batting average. This is just one example. The ballpark singles are designed to help with these type of parks. Oakland has huge foul territory which helps depress batting average

SteveF is on the right track.

One would think ballpark singles would correlate to two things:
(1) Foul territory -- A foul popup in Oakland caught on the edge of the warning track in front of the home dugout is in the 10th row in Fenway park -- giving extra strikes to the Boston batter and requiring extra strikes of the pitcher to retire the batter.
(2) Expansiveness of the outfield. Fenway's RF is large compared with its LF... with more opportunities for popups to find a hole between the infielders and the outfielders. Coors Field's foul territory isn't terribly big or small, but there's so much outfield for the three OF to cover that it gets perennially high ballpark single ratings.

Ballpark singles and HR are also a mechanism to give credit to players who toil in parks ill-suited to their position (hitters who play in pitchers' parks/pitchers who play in hitters' parks)... and, in effect penalize players whose homes are parks suited to their bread and butter. In a season where Jay Bruce has 25% more HR/PA than Giancarlo Stanton, they might end up with identical quantities of automatic HR and ballpark HR on their cards... because Bruce's home is a 1-19 park and Stanton's is a HR 1 park and the game would presume that Bruce's total results from a number of fly balls that would be HR in Cincinnati but not in Miami.