Most of the public discussion of ballpark effects is of the extremes. We know that Coors Field in Colorado sees a lot of home runs because of the altitude and we know that Safeco Field in Seattle and PETCO Park in San Diego see fewer home runs because of their dimensions. The perception of those bookends is correct, but it is not comprehensive. They are not the only parks that have dramatic effects on the run environment.

We measure park factors in indices that compare statistics compiled by both teams in a specific home park and then in all other parks. If a park has an index of 110 in home runs, for example, it allows 10 percent more home runs than average. If a park has an index of 90 in home runs, it allows 10 percent fewer home runs than average. The Bill James Handbook 2013 has a variety of park indices for all 30 teams. Let’s look at a few interesting examples.

Here are the most hitter-friendly ballparks since 2010:

It is little surprise to see Coors Field on top of the list for runs. Colorado sees 21 percent more runs than the next closest park, which is Rangers Ballpark in Arlington. The rest of the list is less differentiated and features a pair of AL East venues, Fenway Park in Boston and Yankee Stadium in New York, as well as U.S. Cellular Field in Chicago and Chase Field in Arizona.

Here are the parks that have allowed the most home runs since 2010:

Home runs are a large part of the high overall run environment in Colorado, but Coors Field is not the only park to play to that extreme. In fact, U.S. Cellular Field has been its equal in home runs for the past three years, with both parks surrendering 38 percent more home runs than average. A couple of NL Central parks, Great American Ballpark in Cincinnati and Miller Park in Milwaukee, are close behind. Yankee Stadium and Rangers Ballpark in Arlington round out the top-six.

Here are parks that have allowed the fewest foul outs since 2010:

New to The Bill James Handbook 2013 is the Foul Outs Index, which generally corresponds to those parks that have the least and the most foul ground in which to convert extra outs on foul popups and flyballs. Once again, Coors Field is on top. Home runs and foul outs represent two of the three biggest hitter advantages in Colorado by percentage, with triples being the third. Fenway Park is famous for having stands up against the foul lines, but Angel Stadium of Anaheim is not much roomier. Rangers Ballpark in Arlington and Wrigley Field in Chicago are tied for fourth-friendliest for hitters, and AT&T Park in San Francisco and Kauffman Stadium in Kansas City are tied for sixth-friendliest.

Here are the most pitcher-friendly ballparks since 2010:

On the other end of the spectrum, Safeco Field allows the fewest runs in baseball. Seattle, San Francisco, and San Diego were the easy guesses on the list. Tropicana Field and Angels Stadium of Anaheim are lesser known as pitchers parks, and yet both have been more pitcher-friendly than even PETCO Park. The Index for Citi Field includes just the numbers from 2012, after they moved in the fences. Surprisingly, the run environment became more depressed after the changes despite the increase in home runs. From 2009 to 2011, Citi Field had a Runs Index of 91 and a Home Runs Index of 83. In 2012, Citi Field had a Runs Index of 87 but a Home Runs Index of 109. We like to look at three years of data to get a handle on a park’s true tendencies. This drop in the Run Index at Citi Field may be a one-year aberration.

Here are parks that have allowed the fewest home runs since 2010:

Marlins Park opened in 2012 and fell short of only AT&T Ballpark in home run prevention. The old Sun Life Stadium was much closer to neutral with a Home Run Index of 94 from 2009 to 2011. One wonders how many home runs that could cost Giancarlo Stanton over his career. Safeco Field, PETCO Park, and Angel Stadium of Anaheim make this list, as well. PNC Park in Pittsburgh and O.co Coliseum in Oakland tie for third and sixth, respectively.

Here are parks that have allowed the most foul outs since 2010:

Finally, Tropicana Field in Tampa Bay and O.co Coliseum in Oakland are the clear leaders in foul outs allowed. They allow 39 percent and 36 percent more foul outs than average. No other ballpark exceeds the 21 percent of Comerica Park in Detroit. List frequenter Safeco Field is just behind with an index of 120. U.S. Cellular Field is next, and Busch Stadium in St. Louis rounds out the list as the only NL park with a Foul Outs Index greater than 10 percent above average.

These and many other park indices for all parks can be found in The Bill James Handbook 2013.