Stats corner: Pirates' pitchers having historic season with grounders, no HRs
Pirates pitchers have adopted a scorched earth policy this season, generating ground balls a major league-high 52.8 percent of the time that hitters put the ball in play. Charlie Morton (65 percent ground ball rate) garners headlines as the game's pre-eminent worm-burner, but fellow starters A.J. Burnett (56.3 percent), Jeff Locke (53.3), Francisco Liriano (51.4) and Gerrit Cole (50) all have induced ground balls far more frequently than the 44.5 percent MLB average. In the bullpen, Mark Melancon (60.5), Bryan Morris (58.4), Jeanmar Gomez (57.3), Justin Wilson (52.4) and Vin Mazzaro (52.2) keep infielders busy.
In fact, the 2013 Pirates are the most ground ball-centric staff in more than a decade. They have the highest single-season team ground ball rate in the majors dating to 2002, the first year for which Fangraphs.com has detailed batted ball data.
Ground and pound
The Pirates have MLB's best ground-ball rate in past 11 years.
Team Year GB Pct.
Pirates 2013 52.8
Cardinals 2005 50.7
Braves 2010 49.9
Cardinals 2009 49.8
Dodgers 2008 49.6
By waging a ground assault, the Pirates have surrendered the fewest home runs per nine innings (0.63) among MLB clubs this season. They also are preventing homers like few other pitching staffs in franchise history.
Since the live ball era began in 1920, only a handful Pirates clubs have prevented home runs at a better clip relative to the National League average. This year's staff ranks fifth during the live ball era in HR+, which compares a team's home runs allowed to the NL average that season and puts it on a scale where 100 is average. The 2013 Pirates have allowed 30 percent fewer home runs than the NL average, the franchise's best showing since in nearly half a century:
No long ball
This year's staff ranks among the best in Pirates history at preventing HRs compared to NL average (since 1920).
Year Pirates HR/9 NL HR/9 HR+
1921 0.24 0.4 60
1946 0.33 0.5 66
1965 0.54 0.8 68
1924 0.27 0.4 68
2013 0.63 0.9 70