A statistic called the park factor compares home runs hit at a team’s home field compared to their road games for both the home team and the visiting team. Based on data from the 2002-2003 seasons, the easiest park was Montreal’s second home park, Hiram Bithorn Stadium in Puerto Rico. The park factor of 181 means there were 81% more home runs per game hit there than in the average National League park.

The easiest parks:

• Montreal, Hiram Bithorn Stadium - 181
• Colorado, Coors Field - 142
• Texas, The Ballpark in Arlington - 132
• Chicago, U.S. Cellular Field - 130

The toughest parks:

• San Francisco, Pacific Bell Park - 66
• Florida, Pro Player Stadium - 79
• Tampa Bay, Tropicana Field - 81
• Detroit, Comerica Park - 81

It’s remarkable that Barry Bonds, only the third member of the 700 Home Run Club in baseball history, plays his home games in the toughest home run park in baseball. Pacific Bell Park, with its park factor of 66, allows 34% fewer home runs than other National League parks.​