Last time, we looked at cumulative run differentials as a way of evaluating an organization’s farm system. We’re going to revisit that idea, but this time we’ll attempt to adjust for age. Organizations, natch, have different drafting strategies and promotion philosophies, which leads to some age variance from level to level. Age relative to peer group is a vital analytical component when scrutinizing individual prospects, and it should also be a factor on the systemic level. And so it shall be.

Another change this time around is that I’ve narrowed the focus to each organization’s full-season affiliates (Triple-A, Double-A, High-A and Low-A). I made this decision because you see quite a bit of variation in how teams flesh out the lower rungs of their systems. For instance, in 2003 nine teams opted to field multiple rookie-level teams and no short-season affiliate at all. This makes system-wide comparisons at the lower levels a bit nettlesome and misleading. I’d also suggest that it’s appropriate to place the emphasis on those levels closest to the major leagues.

Here are the average ages for each organization’s full-season affiliates, ranked youngest to oldest:

1.  Braves                      23.14
2.  Twins                       23.18
3.  Indians                     23.50
4.  Devil Rays                  23.51
5.  Diamondbacks                23.52
6.  Cubs                        23.58
7.  Mets                        23.64
8.  Angels                      23.70
9.  Padres                      23.72
10. Dodgers                     23.73
11. Blue Jays                   23.78
12. Athletics                   23.84
12. Mariners                    23.84
14. Rangers                     23.86
15. Expos                       23.93
16. White Sox                   24.00
17. Yankees                     24.06
18. Pirates                     24.09
19. Tigers                      24.15
20. Giants                      24.25
21. Brewers                     24.28
22. Red Sox                     24.31
23. Marlins                     24.38
23. Phillies                    24.38
25. Orioles                     24.40
26. Royals                      24.44
27. Reds                        24.49
28. Rockies                     24.54
29. Cardinals                   24.65
30. Astros                      24.97

And here are the unadjusted cumulative run differentials for each organization’s four full-season affiliates:

1.  Athletics                   +426
2.  Indians                     +378
3.  Mariners                    +336
3.  Pirates                     +336
5.  Royals                      +195
6.  Rockies                     +159
7.  Marlins                     +87
8.  Devil Rays                  +67
9.  Blue Jays                   +42
10. Diamondbacks                +31
11. Yankees                     +27
12. Mets                        +21
13. Braves                      +16
14. Padres                      -9
15. Dodgers                     -24
16. Twins                       -32
17. Reds                        -37
18. Rangers                     -38
19. Cubs                        -73
20. Orioles                     -76
20. White Sox                   -76
22. Red Sox                     -109
23. Angels                      -113
24. Astros                      -120
25. Tigers                      -154
26. Cardinals                   -167
27. Expos                       -215
27. Phillies                    -215
29. Brewers                     -296
30. Giants                      -382

The problem with adjusting for age is that the low variance among ages (standard deviation = 0.43) relative to run differentials (standard deviation = 188.65) means that the importance of age is likely to be severely downplayed in any kind of quick-and-dirty factoring setup. By that I mean calculating a “park factor” proxy using ages and refiguring runs that way usually yields an adjustment of around 1.5 runs; that’s plainly undervaluing the effect that age differences should have on the final figure.

So I’ve decided to go with an approach that places more weight on average ages. Here’s how it goes: Organizations will receive scores based on how many standard deviations they were better or worse they were than the mean run differential and mean age of all 120 full-season affiliates. (Incidentally, this methodology owes at least a little something to Rob Neyer’s and Eddie Epstein’s excellent book from a few years ago. Furthermore, the scores will be weighted by a factor of 6.7 for the run differential standard deviation score and 3.3 for the age standard deviation score. Then the sum of the two numbers will yield what I’ll call the Farm Score.

Why the 67/33 breakdown? Mostly, I chose it arbitrarily. Although age relative to peer group is vitally important, in my mind it’s not as critical as actual performance, so age receives less emphasis than run differential but far, far more than it would under a park factor-style adjustment. If you think I’m wrong, ping me with an e-mail and let me know what you think the breakdown should be and why. Hey, if you want scientific, then go read one of Nate’s columns.

Without further pomp, here are the Farm Score rankings:

Team                    Farm Score

1.  Indians              17.30
2.  Athletics            16.36
3.  Mariners             13.15
4.  Pirates              11.24
5.  Braves                7.20
6.  Devil Rays            6.17
7.  Twins                 5.16
8.  Diamondbacks          4.82
9.  Royals                3.59
10. Mets                  3.50
11. Blue Jays             3.23
12. Padres                1.81
13. Rockies               1.56
14. Dodgers               1.27
15. Cubs                  0.67
16. Yankees               0.55
17. Marlins               0.16
18. Rangers              -0.27
19. Angels               -1.72
20. White Sox            -2.68
21. Reds                 -5.03
22. Orioles              -5.75
23. Red Sox              -6.27
24. Tigers               -6.58
25. Expos                -8.24
26. Cardinals            -10.89  
27. Astros               -11.66
28. Phillies             -11.70
29. Brewers              -12.67
30. Giants               -15.45  

As you can see, the Indians, A’s, Mariners and Pirates held up nicely under the new method. The Angels and Reds plummeted (mostly because the bulk of their positive overall run differentials were tied up in one or more of their rookie-league affiliates), but the Cubs and Padres both made quantum leaps up the rankings.

The system could be improved by perhaps finding some empirical way to appropriately weight run differential and average age, and a method for accounting for the extreme low minors without falling into an apples-and-oranges quandary would also help. In the near future, I’ll take a whack at both.

You need to be logged in to comment. Login or Subscribe

Baseball Prospectus uses cookies on this website. They help us to understand how you use our website, which allows us to provide an improved browsing experience. Cookies are stored locally on your computer or mobile device and not by BP. To accept cookies continue browsing as normal. You will see this message only once. Privacy Policy

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. See the BP Cookie Policy for more information. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.