EWSL 2009 Age and Rookie Baselines

It’s time once again for my annual division previews using Established Win Shares Levels, which are explained here. Before we get to rolling out the 2009 EWSLs, I have to update the age adjustments and rookie values I use. These are based on the data I have gathered over the past five seasons, and so with each passing year, one would hope they become progressively more stable and useful (how accurate EWSL was in 2008 is another day’s story, but of course as I always remind my readers, EWSL doesn’t predict the future, it just provides a rough count of the talent on hand).
First up is the age adjustments; I’ve reformatted the table a bit from past years (see my writeups on the age adjustments following the 2004 season – also here2005, 2006 and 2007.

2008 Non-P Total Non-P
Age # WS EWSL % # WS EWSL %
21- 0 0 0 0 4 33 34 0.971
22 4 46 33 1.394 24 378 194.9 1.940
23 11 93 100 0.930 46 595 462.5 1.286
24 23 353 262 1.347 83 1129 873.3 1.293
25 27 371 330 1.124 115 1348 1098 1.227
26 27 280 257 1.089 145 1580 1393 1.135
27 39 351 322 1.090 163 1790 1711 1.046
28 38 426 428 0.995 175 2118 2059 1.029
29 24 330 315 1.048 155 1862 1986 0.937
30 28 296 309 0.958 174 1888 2156 0.876
31 26 228 307 0.743 154 1606 1941 0.827
32 39 404 524 0.771 148 1514 1841 0.822
33 20 147 223 0.659 115 1170 1402 0.835
34 23 241 317 0.760 101 1031 1201 0.858
35 5 47 55 0.855 89 678 975.7 0.695
36 19 211 252 0.837 71 673 879.8 0.765
37 7 72 87 0.828 48 390 594.3 0.656
38 7 43 65 0.662 33 274 380.5 0.720
39 2 13 23 0.565 26 273 347.8 0.785
40+ 6 36 89 0.404 30 228 423.7 0.538
All NP 375 3988 4298 0.928 1899 20558 21955 0.936

As you can see, there were the usual annual variations from historic norms, but the overall 5-year results are still pretty stable, showing that non-pitchers as a group improve rapidly in their early 20s, more slowly in their mid-20s, and begin a remorseless downward slide starting at age 29, with ages 35 and 37 being the worst culprits on the south side of 40 for one-year decline (if anything, the aggregate numbers conceal the extent of the decline because of people dropping out of the sample – note that a third of the guys who have jobs at age 30 are gone from the preseason depth charts by age 33). The interesting question is whether these trends have been skewed by steroid use; I note that in 2008, the decline rates for hitters in the age 31-34 bracket and the age 38-and-up bracket were unusually steep by historic standards. (The 35-year-old cohort was extremely small this year due to a lot of guys hitting the wall early). It was also a rough year for 23-year-olds, but that seems more like random noise.
I’ve included, for the first time, a total line for all ages at the bottom, and you can see that the average non-pitcher comes up 6.4% short of established levels in any given year. When you think about it, that’s not really surprising.

2008 P Total P
Age # WS EWSL % # WS EWSL %
21- 0 0 0 0 8 56 38 1.474
22 6 37 35 1.057 26 192 166.6 1.152
23 10 73 54 1.352 47 342 327.8 1.043
24 22 222 137 1.620 80 565 498.4 1.134
25 23 139 134 1.037 108 741 669.4 1.107
26 31 181 187 0.968 135 898 839.2 1.070
27 25 194 225 0.862 127 899 944.6 0.952
28 14 73 112 0.652 137 943 956.3 0.986
29 31 259 260 0.996 138 914 1036 0.882
30 30 151 191 0.791 128 742 870.4 0.852
31 25 181 175 1.034 109 715 836.5 0.855
32 15 94 113 0.832 84 495 676.5 0.732
33 14 76 122 0.623 71 380 544.3 0.698
34 6 14 32 0.438 56 262 386.6 0.678
35 6 35 39 0.897 44 206 314.2 0.656
36 9 50 68 0.735 39 219 254.2 0.862
37 8 31 51 0.608 33 223 264.3 0.844
38 6 45 55 0.818 34 234 293 0.799
39 2 23 15 1.533 21 164 177.3 0.925
40+ 13 68 119 0.571 55 398 539.3 0.738
All P 296 1946 2124 0.916 1480 9588 10633 0.902

The pitchers are by nature more volatile – you will notice that the average pitcher is apt to be off closer to 10% over the 5-year period. It was a freakishly good year for 23-24-year-old pitchers, as well as age 31 and age 39 (the latter being basically Mike Mussina), and crummy for everyone else; the age 28 and 34 groups, already smaller than their surrounding age cohorts, got slaughtered. The overall 5-year pattern remains one of decline for pitchers in every age group above 26, with brutal attrition rates beyond age 32. Pitching is rough business.

Type of Player # in 2008 WS in 2008 # 2004-08 WS 2004-08 Rate
Everyday Players 10 104 52 585 11.25
Bench Players (Under 30) 4 4 44 159 3.61
Bench Players (Age 30+) 1 0 3 2 0.67
Rotation Starters 4 16 18 77 4.28
Relief Pitchers 0 0 11 65 5.91
TOTAL 19 124 128 888 6.94

The rookie adjustments remain, along with the ad hoc fudge factor, the most glaringly unscientific part of this enterprise, but I need some less than wholly random way to plug in the rookies, and at least for everyday players the rough guideline that has them around 11 Win Shares a year for rookies with everyday jobs mostly holds up. Rookie starting pitchers, of course, will break your heart.