to plunk and get plunked

You probably already knew that Craig Biggio has been hit by 285 pitches thrown by 213 different pitchers. But did you know that those 213 pitchers have been hit a total of 131 times themselves, by only 111 different pitchers? And of the 131 plunks that landed on a pitcher who has plunked Biggio, 57 were thrown by another pitcher who also plunked Biggio. 41 pitchers have both hit Craig Biggio with a pitch, and plunked at least one other pitcher who plunked Biggio. So, 43.5% of the plunks that hit pitchers who plunked Biggio were thrown by pitchers who plunked Biggio, but in the National League, between 1988 and 2006, only (only?) 37.1% of all the HBPs thrown were thrown by pitchers who have plunked Biggio.

Andy Benes and Bob Walk were each hit by 6 pitches in their careers, making them the leaders in the getting hit category among those who have hit Craig Biggio with pitches. Greg Maddux, Kevin Brown, Pedro Astacio and Oral Hershiser all have 5 career plunks to their credit, and Livan Hernanez, Mark Gardner, Matt Clement and Darryl Kile have 4 each. Biggio has been hit by Pedro Astacio more times than any of those guys have been hit, and none of them has been hit more times in their career than Biggio has on April 29th alone. All 4 of Darryl Kile's career plunks came while batting for the Astros, and Mark Portugal, Pete Harnisch and Ron Villone all recorded their only career plunks (1 each) while playing for Houston.

All 6 of the times Andy Benes was plunked, the pitch was thrown by someone who has plunked Craig Biggio, but none of Bob Walk's 6 plunks were thrown by Biggio plunkers. Matt Clement was also plunked exclusively by pitchers who have plunked Biggio.

Of those 213 pitchers who have plunked Biggio, only 54 have as many career plunks as they've inflicted on Biggio alone.

Darryl Kile and Greg Maddux are tied for the record for hitting other pitchers who plunked Biggio, with 4 plunks each. Maddux hit Steve Cooke, Jason Jennings, Dustin Hermanson and Dontrelle Willis, while Daryl Kile hit Scott Karl, Andy Benes and Kevin Ritz twice. DK plunked Ritz twice in the same game, making Ritz the only pitchers who has plunked Biggio and been hit twice himself in one game. Coincidently, Ritz had plunked Kile in their previous meeting. Kile also plunked Ritz before either had plunked Biggio, and Kile was pitching for the Astros at the time.

Of the 131 times pitchers who have plunked Biggio have been plunked themselves, only 10 of those HBPs were thrown by the Astros (including the 2 Kile threw at Ritz), and only 2 were cases where the pitcher had plunked Biggio before getting plunked by the Astros. Willie Banks is the only pitcher to plunk Biggio and get plunked in the same game, but Banks got hit first. Jason Marquis is the only pitcher to plunk Biggio and then get hit by the Astros in the same season. Only 77 of the 131 plunks recorded by pitchers who plunked Biggio were actually recorded after each pitcher hit Biggio for the first time.

Here's the complete (to date) history of pitchers who have plunked Biggio plunking each other:
Tom Browning hit Mike LaCoss on 6/8/1987, John Smiley hit Greg Maddux on 9/16/1989, Ryan Bowen (of the Astros) hit Andy Benes on 8/8/1991, Mark Portugal (of the Astros) hit Andy Benes on 9/9/1991, Jose DeLeon hit Andy Benes on 7/2/1993, Greg Maddux hit Steve Cooke on 7/16/1993, Ryan Bowen hit Pete Harnisch on 8/26/1993, Kevin Ritz hit Darryl Kile (of the Astros) on 8/4/1994, Darryl Kile (of the Astros) hit Kevin Ritz twice on 4/28/1995, Jaime Navarro hit Pedro Martinez on 7/25/1995, Mark Thompson hit John Smoltz on 6/9/1996, Mark Thompson hit Tom Candiotti on 7/6/1996, John Smiley hit Paul Wilson on 7/26/1996, Mark Leiter hit Mark Gardner on 8/23/1996, Steve Cooke hit Shawn Estes on 5/1/1997, Tim Worrell hit Jeff Juden on 5/14/1997, Danny Jackson hit Shawn Estes on 6/24/1997, John Franco hit Rob Stanifer on 7/3/1997, Pedro Astacio hit Andy Benes on 7/7/1997, Tom Candiotti hit Darryl Kile on 9/13/1997, Joel Adamson hit Danny Darwin on 4/4/1998, Pete Harnisch hit Garrett Stephenson on 4/23/1998, Jeff Juden hit Pedro Astacio on 5/18/1998, Darryl Kile hit Andy Benes on 6/1/1998, Chan Ho Park hit Livan Hernandez on 8/21/1998, Stan Spencer hit Paul Byrd on 8/27/1998, Stan Spencer hit Shawn Estes on 4/8/1999, Donovan Osborne hit Jason Bere on 4/11/1999, Chan Ho Park hit Andy Benes on 8/1/1999, Paul Byrd hit Stan Spencer on 8/24/1999, Kevin Brown hit Livan Hernandez on 9/29/1999, Darryl Kile hit Scott Karl on 4/13/2000, Todd Ritchie hit Rick Reed on 5/10/2000, Jimmy Anderson hit Paul Byrd on 7/21/2000, Brian Bohanon hit Kevin Brown on 9/8/2000, Brian Bohanon hit Kevin Brown on 5/29/2001, Shawn Estes hit Kevin Brown on 6/26/2001, Randy Wolf hit Greg Maddux on 10/2/2001, Al Leiter hit Brian Anderson on 4/30/2002, Kevin Brown hit Matt Clement on 5/5/2002, Everett Stull hit Matt Clement on 5/10/2002, Kris Benson hit Matt Clement on 5/28/2002, Greg Maddux hit Jason Jennings on 8/18/2002, Matt Clement hit Rick Helling on 8/18/2002, AJ Burnett hit Vicente Padilla on 4/14/2003, Juan Cruz hit Salomon Torres on 4/20/2003, Brandon Webb hit Ron Villone on 6/23/2003, Matt Clement and Danny Haren plunked each other on 9/3/2003, Greg Maddux hit Dustin Hermanson on 5/20/2004, Shawn Estes hit Chris Capuano on 6/23/2004, Jason Marquis hit Russ Ortiz on 8/14/2004, Brandon Webb hit Brian Moehler on 8/11/2005, Greg Maddux hit Dontrelle Willis on 8/27/2005, Matt Morris hit Glendon Rusch on 9/16/2005 and Matt Morris hit Aaron Cook on 5/26/2007.

Only 3 pairs of Biggio plunkers have plunked each other - Darryl Kile and Kevin Ritz, Matt Clement and Dan Haren, and Stan Spencer and Paul Byrd - but only Clement and Haren did it in the same game.