Baseball America released their three-year park factors for every minor league stadium in full-season ball this week, and it's no real surprise to see Mets affiliates at the the tippy-top and very bottom of the spectrum. First, let's go to the raw numbers. Keep in mind that for park factors, 100 is neutral. Lower than that means the park favors pitchers, higher favors batters.
Las Vegas (AAA: 12.81 Runs/Game (6th most in all of the minors), Park Factor of 109
Binghamton (AA): (9.59 Runs/Game, Park Factor of 100
St. Lucie (A+): 9.57 Runs/Game, Park Factor of 109
Savannah (A): 7.00 Runs/Game (fewest in the minors), Park Factor of 88
These listed park factors are relative to league, not all of minor league baseball, so while St. Lucie and Binghamton have almost identical runs/game, St. Lucie has a higher park factor, because the Florida State League on the whole is a lower offensive environment.
It's no surprise to see Las Vegas near the top of the list in runs per game. The Mets preferred to avoid Vegas and the PCL in general for just this reason. Overall, the Pacific Coast League ranked second only to the California League in hitter-friendliness, and of the five teams ahead of Las Vegas in runs per game, three were from the PCL Pacific Division. Overall the league had six of the top ten offensive environments in all of minor league baseball.
It's also not much of a shock to see Savannah at the bottom of this list. Historic Grayson Stadium gets a closer look from BA, but to sum up, the combination of high fences, big power alleys, proximity to sea level, and the humid Georgia air all combine to create the most pitcher-friendly park in full-season baseball. And having been to Savannah myself, I can confirm that it is a massive, massive park, especially in those power alleys. To try and make this a little more concrete, let's look as Mets prospect Aderlin Rodriguez, who has the most raw power of any player in the system. He posted a .782 OPS in Savannah and a .891 OPS on the road in 2012. Another minor leaguer with some real pop in his bat, Travis Taijeron, slugged almost 200 points higher away from Historic Grayson Stadium.
Of course you should always take minor league stat lines in general with a healthy dose of NaCl, and a low park factor doesn't mean that Domingo Tapia and Michael Fulmer were mere products of their environment or that Aderlin Rodriguez's swing will work at higher levels. But it is important to calibrate your expectations when looking at minor league box scores. There's no need to panic if Brandon Nimmo is slugging .370 at the South Atlantic League all-star break, and likewise no need to bang a drum for a Juan Lagares promotion if he's leading the PCL in hitting.