Let's call it the winter of ballpark-conscious transactions.
More than ever before, teams seemed to make moves with their ballparks in mind, attempting to match player skills to their home venues. For example, Evan Gattis landed in Houston, where he can take aim at the Crawford Boxes in Minute Maid Park. Josh Donaldson and Russell Martin left pitching-friendly ballparks and landed in Toronto and its hitter-friendly Rogers Centre. The Miami Marlins, meanwhile, brought Mat Latos in to pitch in their spacious ballpark.
That's not to say that all winter moves were positive -- Matt Kemp's move from Dodger Stadium to Petco Park being one of the negatives -- but with so many moves having obvious ballpark-related implications, it's worth examining what aspects of the game each venue favors. Hitting or pitching? Fly ballers or ground ballers? Right- or left-handers?
One could simply head to our Park Factor page for a quick read on the subject, but there's a limitation to those: They're one-year samples and can be influenced by personnel that called the ballparks their home in that given season. I prefer to take a longer-range -- at least three seasons' worth -- approach, especially examining the annual fluctuations in statistics at each venue.
First up, remember that change doesn't apply to only the players; the ballparks themselves often experience winter adjustments, some of which could have an immediate impact upon the players who call them home.
Ballpark changes for 2015
Three teams made significant changes to their ballpark for 2015, either playing field or the structures themselves. Here are the details of those alterations:
Citi Field (New York Mets): For the second time in the venue's seven-year history, Citi Field's fences were moved closer to home plate, though this year's adjustments weren't as dramatic as those during the winter of 2011-12. The Mets erected a new fence between center and right-center field, bringing the distances five to 10 feet closer to home plate, the deepest part in right-center shrinking from 390 to 380 feet. General manager Sandy Alderson told Mets beat reporters in November that, plotting 2014 batted balls hit to right-center field, 27 additional home runs would've been hit using the new dimensions -- 17 by the Mets and 10 by opponents.
Progressive Field (Cleveland Indians): Though no playing-field adjustments were made -- the fence distances and heights as well as the foul-territory measurements remained unchanged -- the center and right-field seating areas and concourses were renovated this winter. A section of the upper deck was converted into terrace seating, while concrete portions of the right-center-field entrance were removed to create better views from the street, among other changes. According to several Indians beat reporters, team officials conducted wind studies that revealed no significant expected changes. Still, regular-season games will provide us a more definitive answer.
Wrigley Field (Chicago Cubs): As with Progressive Field, no playing-field adjustments were made to Wrigley. A four-year renovation project began this winter which, at least for 2015, will add signage and new video boards in time for Opening Day and new bleachers sometime early in the regular season. And again, as with Progressive Field, team officials conducted wind studies that suggested no major impact, though we'll get a firmer read once regular-season games are underway.
Now, let's approach ballpark factors from both a basic and detailed angle. Listed first are rankings of the nine most hitter- and pitcher-friendly ballparks. At column's end, for the most spreadsheet-inclined readers, are full charts detailing the particular advantages and disadvantages of each venue.
You can get to those from each of these quick links:
Overall ballpark factors: Sortable rankings, in the style of our Park Factors page, for all sorts of statistical categories.
Ballpark batted-ball breakdowns, RHB 2012-14: Ballpark statistics for right-handed hitters, broken down by field direction.
Ballpark batted-ball breakdowns, LHB 2012-14: Ballpark statistics for left-handed hitters, broken down by field direction.
Current MLB ballpark dimensions: All measurements to five different directions of the playing fields, including fence heights.
Nine most hitter-friendly ballparks
This is a somewhat subjective list but accounts for run-scoring, home run, extra-base hit and overall BABIP/hit rate statistics in recent seasons. Specific hitter/pitcher tendencies are noted.
1. Coors Field (Colorado Rockies): Notwithstanding its mediocre consistency grade at chart's end -- that being more a product of run fluctuations at the highest end of the scale -- Coors is easily baseball's friendliest hitting environment, thanks to its mile-high altitude. The Rockies' own official website provides a simple explanation as to why: "... the ball still travels 9 percent farther at 5,280 feet than at sea level. It is estimated that a home run hit 400 feet in sea-level Yankee Stadium would travel about 408 feet in Atlanta and as far as 440 feet in the Mile High City." In addition, distant outfield fences provide spacious confines that allow additional extra-base hits to drop in. It's why Coors has seen a .339 BABIP (batting average on balls in play) the past three seasons combined, highest in the league by 19 points. New, notable Rockies: Nick Hundley.
2. Rogers Centre (Toronto Blue Jays): Surprise, surprise, but what earns Rogers Centre the No. 2 ranking is how balanced an offensive environment it is; it's good for run scoring (sixth-best factor from 2010 to '14), power (seventh-best from 2012 to '14), extra-base hits (second-best venue for doubles from 2012 to '14) and, despite better metrics for right- than left-handed hitters, was still top 10 for the latter. It has also been consistently hitter-friendly, indicated by the "B" grade in the chart at column's end; this grades how much the numbers have fluctuated from year to year. New, notable Blue Jays: Josh Donaldson, Marco Estrada, Russell Martin, Michael Saunders, Justin Smoak, Devon Travis.
3. Chase Field (Arizona Diamondbacks): It's another park ranked highly due to its balance; the only negative is that it's a poor environment for power to straightaway center field, due to its 25-foot fence. It is an especially good venue for right-handed power -- righties had the third-best home run/fly ball percentage in baseball there the past three seasons combined -- which is a plus considering the Diamondbacks' power is predominantly right-handed. New, notable Diamondbacks: Rubby De La Rosa, Yasmany Tomas, Allen Webster.
4. U.S. Cellular Field (Chicago White Sox): It's renowned for being a homer-friendly environment, but from 2010 to 2014, U.S. Cellular actually inflated run scoring by nine percent, fifth best in baseball. New, notable White Sox: Emilio Bonifacio, Melky Cabrera, Zach Duke, Adam LaRoche, David Robertson, Jeff Samardzija.
5. Miller Park (Milwaukee Brewers: It's one of the sneakier hitters' venues; few fantasy owners, if asked to recite a list from memory, would think of it as one of the top five. But from 2012 to 2014, it was the eighth-best run-scoring and third-best home run environment in baseball. Strangely, it is especially homer-friendly to straightaway center; 10 percent of the fly balls hit to center field the past three seasons cleared the fence, tops in baseball. New, notable Brewers: Adam Lind.
6. Great American Ball Park (Cincinnati Reds): From 2012 to 2014, no venue has been more homer-friendly; Great American inflated home run production by 40 percent, more than Coors (36 percent). It was most favorable for left-handers, thanks to its 325-foot distance down the right-field line and 370 to right-center, even if the ballpark is merely above average for run scoring. New, notable Reds: Marlon Byrd.
7. Yankee Stadium (New York Yankees): Everyone thinks of it as a homer haven, but the truth is that the only extreme park factor at Yankee Stadium is left-handed power, particularly those with extreme pull tendencies. From 2012 to '14, left-handed batters, when putting the ball into play to right field there, combined for .371 isolated power with 40 percent of their fly balls clearing the fence; those were by far major league bests. This is the kind of park in which, on an individual matchups basis, it's wise to load up on left-handed power bats while avoiding fly ball pitchers, especially right-handers. New, notable Yankees: David Carpenter, Nathan Eovaldi, Didi Gregorius, Garrett Jones, Andrew Miller, Justin Wilson.
8. Fenway Park (Boston Red Sox): It's like the reverse Yankee Stadium; the Green Monster in left field helps inflate right-handed hitting numbers. Power to left field might not be much more than league average -- it had only the 14th-best home run factor the past three seasons -- but right-handed hitters had a .353 BABIP to left field, tops in baseball. Unlike Yankee Stadium, though, Fenway is below average for left-handed hitters. Mind your visiting pitchers with extreme platoon splits. New, notable Red Sox: Ryan Hanigan, Justin Masterson, Wade Miley, Rick Porcello, Hanley Ramirez, Pablo Sandoval.
9. Camden Yards (Baltimore Orioles): A 318-feet distance to the right-field pole, in spite of the fence's 25 feet in height, makes this a slightly better venue for left- than right-handed power, but Camden Yards is a well above-average environment for power and extra-base production. New, notable Orioles: Travis Snider.
Nine most pitcher-friendly ballparks
Again, it's a somewhat subjective list but accounts for run-scoring, home run, extra-base hit and overall BABIP/hit rate statistics in recent seasons. Specific hitter/pitcher tendencies are noted.
1. AT&T Park (San Francisco Giants): Forget the Barry Bonds days. AT&T Park has an outrageous 421-feet measurement to the right-center fence, which is 21 feet in height, and it severely deflates left-handed power accordingly. Only 19 percent of the time a lefty pulled the ball there did it clear the fence from 2012 to 2014, easily worst in baseball. By the way, right-handed power hasn't fared especially well there during that span, either, as the chart at column's end shows. New, notable Giants: Norichika Aoki, Casey McGehee.
2. PNC Park (Pittsburgh Pirates): No park in baseball mutes right-handed power more than PNC Park; Pirates hitters and their opponents had 42 percent less home run production there than in Pirates road games from 2012 to 2014. It's also a noticeably below-average venue for left-handed power due to the 25-foot fence in right field. Oddly, PNC had better-than-average power numbers to straightaway center field. Notable, new Pirates: Antonio Bastardo, A.J. Burnett, Francisco Cervelli, Jung-Ho Kang, Sean Rodriguez.
3. Safeco Field (Seattle Mariners): Despite moving in the fences following the 2012 season, Safeco remains a pitching-friendly venue. To compare before and after those adjustments, Safeco had a 0.781 run-scoring park factor (i.e., it deflated run scoring by approximately 22 percent) from 2010 to 2012 but a 0.911 factor in the past two seasons combined. Even with those changes, it's a poor park for right-handed power, which is bad news for free-agent signee Nelson Cruz. New, notable Mariners: Cruz, J.A. Happ, Justin Ruggiano, Seth Smith.
4. Tropicana Field (Tampa Bay Rays): Though it's not traditionally thought of as a pitchers' park, Tropicana indeed is, which has presumably contributed to the team's pitching success during the past decade. It was the fifth worst for run scoring the past five seasons and eighth worst for both home runs and extra-base hits the past three years combined. It's also fairly balanced as to reining in right- and left-handed hitters' stats. New, notable Rays: Asdrubal Cabrera, Juan Francisco, Ernesto Frieri, John Jaso, Kevin Jepsen, Rene Rivera, Daniel Robertson, Steven Souza.
5. Angel Stadium (Los Angeles Angels): Despite some of the star power in the Angels' lineup, their ballpark does quite a job of reining in offensive numbers. Angel Stadium had the fourth-worst runs scored park factor from 2010 to 2014, and it's especially rough on left-handed power: In the past three seasons it suppressed lefties' home runs by 21 percent, with only 25 percent of lefties' fly balls hit to right field clearing the fence; both of those ranked among the bottom five in baseball. That 18-foot fence from right to right-center field doesn't help. New, notable Angels: Andrew Heaney, Matt Joyce, Josh Rutledge.
6. Petco Park (San Diego Padres): Like Safeco, Petco experienced an outfield-fence makeover following the 2012 season, the team moving in the fences in an attempt to rein in what was then by far the worst environment for left-handed hitters. While it did improve matters, lefties enjoying the 23rd-ranked park factor for home runs there from 2012 to 2014 -- that a big jump from what was routinely 30th -- it didn't actually improve run scoring: Petco had a 0.852 park factor from 2010 to 2012 and 0.828 in 2013-14. This is still one of the game's most pitching-friendly environments. New, notable Padres: Tim Federowicz, Shawn Kelley, Matt Kemp, Brandon Maurer, Will Middlebrooks, Brandon Morrow, Wil Myers, Derek Norris, Justin Upton.
7. Marlins Park (Miami Marlins): It's an average to slightly above-average run-scoring environment, but power is a problem in Miami, primarily because most of the fence measurements are at least 10 feet deeper than the league's averages. It's also an awful park for power to straightaway center -- only three percent of all balls in play hit there from 2012 to 2014 cleared the fence, third worst to only Minute Maid Park and Comerica Park -- so perhaps the Marlins wanted to protect their home run statue from moon shots while simultaneously saving on their electric bill running it. New, notable Marlins: Aaron Crow, Dee Gordon, Dan Haren, Mat Latos, Michael Morse, David Phelps, Martin Prado, Andre Rienzo.
8. Busch Stadium (St. Louis Cardinals): Though no specific aspect of Busch leans toward the pitching extreme, every statistical aspect of it leans well on the pitching-friendly side of the league's averages, which is strange considering its fence measurements are roughly league average. Incidentally, 2014 was the first time in nine years (2005 the last time) that Busch Stadium had a hitter-leaning number in terms of run production on our Park Factors page. New, notable Cardinals: Matt Belisle, Jason Heyward, Mark Reynolds, Jordan Walden.
9. Dodger Stadium (Los Angeles Dodgers): It's a strange beast, with a pitcher-leaning run-scoring park factor but a hitter-leaning factor in terms of home runs. Left-handed power hitters fared oddly well here from 2012 to 2014, experiencing 18 percent better home run production there than in road games, seventh best in baseball. New, notable Dodgers: Brett Anderson, Yasmani Grandal, Chris Heisey, David Huff, Howie Kendrick, Brandon McCarthy, Juan Nicasio, Joel Peralta, Jimmy Rollins.
Overall ballpark factors
The chart below lists all 30 ballparks with only statistics accrued in the years in which the venue played under its current fence measurements. Factors are calculated using the same formula we use for our Park Factor page; it compares the rate of a team's and its opponents' stats at home to the rate of their stats on the road, with a factor higher than 1.000 favoring the hitter.
The "Runs Factor" uses a five-year analysis (2010-14) for a better read on the ballpark's overall run production, with "Stn'd. Dev." the standard deviation of that number over the five seasons, and "Cons. Grade" the team's letter grade for how consistent the numbers were during that five-year span. Right- and left-handed home run factors ("RH HR Factor" and "LH HR Factor") as well as the extra-base hit factor ("XBH Factor") and the BABIP (batting average on balls in play) at the ballpark in question use three years of data (2012-14).
Ballpark batted-ball breakdowns, RHB 2012-14
The chart below breaks down batted balls hit only by right-handed batters, by direction hit in the venue in question, listing their BABIP, isolated power (ISO) and home run/fly ball percentage (HR/FB). These are only statistics accrued at that park; these are not calculated like the park factors above. Statistics are from the past three years (2012-14).
Ballpark batted-ball breakdowns, LHB 2012-14
The chart below breaks down batted balls hit only by left-handed batters, by direction hit in the venue in question, listing their BABIP, isolated power (ISO) and home run/fly ball percentage (HR/FB). These are only statistics accrued at that park; these are not calculated like the park factors above. Statistics are from the past three years (2012-14).
Current MLB ballpark dimensions
Ballpark measurements include both fence distances from home plate (identified as "dist.") and heights (identified as "hgt."), to five different directions on the playing field. Left-field (identified as "LF") and right-field (identified as "RF") measurements are those directly down the foul lines. Left-center field (identified as "LCF") and right-center field (identified as "RCF") measurements are those provided by the teams and are not necessarily mapped to the same position on the field by ballpark.
For a good resource to compare the dimensions of two different ballparks, try the ESPN Home Run Tracker's Park Overlays tool.