Jeremy Koo reminds me that I've calculated the "generations" various A's players represent: How many trades or compensation draft picks does each player trace back in their acquisition chain to an original A's regular draft pick? A regular draft pick is first generation, as is a free agent. Someone acquired for a first-generation player is a second-generation player. Etc.

I count only through the most important player in a trade. Scott Hairston, for instance, was acquired for Craig Italiano, Ryan Webb and Sean Gallagher. Gallagher was a player to be named later in the deal. Between Italiano and Webb, the former had the better prospect pedigree (second-round pick) and strikeout numbers, and was still a starter; the latter didn't have the former's control problems and had already reached Triple-A. Italiano also had injury issues. It's a tough call, and the Padres probably didn't have a clear idea of who the "headliner" in the deal was, but I'm going to say it's Italiano. (Note that in past versions of this, I've used Gallagher, probably because he actually had something of a major league career; in retrospect, I think this was mistaken and I will be using Italiano as the "main piece" from the deal henceforth.)

So, with the A's winter of discontent now nearly completed, here's how the 40-man roster stands in terms of generations:

First generation (last time: 22)

1. Billy Butler (FA, 2015)
2. Mark Canha (Rule 5, 2015)
3. Jesse Chavez (Cash trade, 2012)
4. Coco Crisp (FA, 2010)
5. Ike Davis (Int'l draft slot trade, 2015)
6. Nate Freiman (Rule 5, 2013)
7. Sonny Gray (1st round, 2011)
8. A.J. Griffin (13th round, 2010)
9. Scott Kazmir (FA, 2014)
10. Arnold Leon (FA, 2008)
11. Renato Nunez (FA, 2010)
12. Eric O'Flaherty (FA, 2014)
13. Dan Otero (Waivers, 2013)
14. Eury de la Rosa (Cash trade, 2015)
15. Evan Scribner (Waivers, 2012)
16. Taylor Thompson (Waivers, 2015)
17. Stephen Vogt (Trade for no player, 2013)

Second generation (last time: 12)

1. Fernando Abad < John Wooten (37th round, 2012)
2. Raul Alcantara < Andrew Bailey (6th round, 2006)
3. Ryan Cook < Trevor Cahill (2nd round, 2006)
4. Sean Doolittle < Barry Zito (1st round, 1999)
5. Craig Gentry < Michael Choice (1st round, 2010)
6. Tyler Ladendorf < Orlando Cabrera (FA, 2009)
7. Jarrod Parker < Trevor Cahill (2nd round, 2006)
8. Josh Reddick < Andrew Bailey (6th round, 2006)

Third generation (last time: 1)

1. Chris Bassitt < Jeff Samardzija < Addison Russell (1st round, 2012)
2. Kendall Graveman < Josh Donaldson < Rich Harden (17th round, 2000)
3. Brett Lawrie < Josh Donaldson < Rich Harden (17th round, 2000)
4. Sean Nolin < Josh Donaldson < Rich Harden (17th round, 2000)
5. Josh Phegley < Jeff Samardzija < Addison Russell (1st round, 2012)
6. Rangel Ravelo < Jeff Samardzija < Addison Russell (1st round, 2012)
7. Marcus Semien < Jeff Samardzija < Addison Russell (1st round, 2012)

Fourth generation (last time: 4)

1. Billy Burns < Jerry Blevins < Jason Kendall < Mark Redman (FA, 2004)
2. Drew Pomeranz < Brett Anderson < Dan Haren < Mark Mulder (1st round, 1998)

Fifth generation (last time: 4)

1. Yunel Escobar < Daniel Robertson¹ < Josh Willingham < Corey Brown < Frank Thomas (FA, 2006)
2. Ben Zobrist < Daniel Robertson < Josh Willingham < Corey Brown < Frank Thomas (FA, 2006)

Sixth generation (last time: 1)

1. R.J. Alvarez < Derek Norris < Gio Gonzalez < Nick Swisher < Johnny Damon < Ben Grieve (1st round, 1994)
2. Sam Fuld < Tom Milone < Gio Gonzalez < Nick Swisher < Johnny Damon < Ben Grieve (1st round, 1994)
3. Jesse Hahn < Derek Norris < Gio Gonzalez < Nick Swisher < Johnny Damon < Ben Grieve (1st round, 1994)
4. Eric Sogard < Scott Hairston < Craig Italiano < Damian Miller < Michael Barrett < Brett Price (14th round, 2001)