A few years ago I did a comparison between 2007 and 2008 home run numbers at Citizens Bank Park for a friend of mine, including temperature and wind profiles...all sorts of fun stuff. You might remember those times when the Phillies had to outslug and outpower the opposition and not win with four aces. In 2007, the Phillies and their opponents combined to hit 241 home runs in 81 games, averaging nearly three home runs per game combined.
Those were the days we grumbled about Adam Eaton and a bunch of other guys whose ERA's were higher than kindergarten ages. These days? Name your reliever...of course, the starters are generally still pretty reliable!
Thanks to improved starting pitching, aging and declining bats, and a turn away from power baseball and towards "old tyme baseball" the power numbers of yore are looking like relics. Power numbers this past season were down 46 percent from 2007.
It certainly has little to do with the weather!
The average temperature at a Phillies game in 2007 was 75.1 degrees and in 2008 it was 74.1 degrees. Even in 2008, the Phillies and opponents combined for 188 home runs. While a steep decline, much of that had to do with the improvement of the Phils' pitching staff from 2007 to 2008 as they gave up forty seven fewer home runs...and the Phillies as a team only hit six fewer home runs over 81 games.
You might have thought the warmest games of the year featured the most offensive fireworks, given the usual propensity of baseballs to travel farther in warmer air due to its lower density. Well, the hottest game of 2011 did feature the most home runs combined (six) of any Phillies game last season...and it was a game where Chad Qualls had a bullpen meltdown for San Diego by giving up three home runs in the heat and getting only one guy out. It also featured the all-star matchup of Mat Latos and Kyle Kendrick.
Helps to have average pitching on a hot day.
The irony of that six home run game is that in the two days surrounding the 100 degree game on July 23rd there was nary a home run in the two games. Starting for the Phillies in those games? Cole Hamels and Roy Halladay, on games with temperatures that were 98 and 94 respectively at first pitch.
The other most powerful games last year were on more "normal" temperature days -- games where the temperature wasn't any higher than 88 degrees...and two games where the game time temp was in the 60's.
The morals of the story? Improved starting pitching can outdo hot weather...and I loathe to see Chad Qualls' performance when we hit summer.