EWSL 2010 Age and Rookie Baselines

It’s time once again, however belatedly, for my annual division previews using Established Win Shares Levels, which are explained here. Before we get to rolling out the 2010 EWSLs, I have to update the age adjustments and rookie values I use each year. These are based on the data I have gathered over the past six seasons, and so with each passing year, one would hope they become progressively more stable and useful in evaluating the established talent base on hand for each team entering each season. As a reminder: EWSL is not a prediction system. It’s a way of assessing the resources on hand. Time, chance, and mid-season replacements happen to all.
First up is the age adjustments; I’ve reformatted the table a bit from year to year. See my writeups on the age adjustments following the 2004 season – also here2005, 2006, 2007, and 2008 seasons. Here’s the 2009 age adjustments (i.e, how each age of non-pitcher or pitcher stacked up to their un-age-adjusted EWSL), and the totals for 2004-09 – in some ways, if you study these sorts of things, the numbers accumulated over this many seasons become interesting in themselves:

2009 Total
Age # WS EWSL % # WS EWSL %
21- 1 19 8 2.375 5 52 42.00 1.238
22 2 36 13 2.769 26 414 207.87 1.992
23 9 99 98 1.010 55 694 560.50 1.238
24 16 163 141 1.156 99 1292 1014.31 1.274
25 36 496 384 1.292 151 1844 1482.40 1.244
26 29 410 387 1.059 174 1990 1779.67 1.118
27 28 327 315 1.038 191 2117 2025.83 1.045
28 35 338 351 0.963 210 2456 2409.53 1.019
29 34 401 407 0.985 189 2263 2393.47 0.945
30 24 353 325 1.086 198 2241 2481.17 0.903
31 31 294 310 0.948 185 1900 2251.04 0.844
32 23 164 259 0.633 171 1678 2099.83 0.799
33 32 349 395 0.884 147 1519 1796.77 0.845
34 15 144 170 0.847 116 1175 1371.33 0.857
35 19 253 265 0.955 108 931 1240.67 0.750
36 5 27 48 0.563 76 700 927.83 0.754
37 14 119 195 0.610 62 509 789.33 0.645
38 6 42 73 0.575 39 316 453.50 0.697
39 1 7 14 0.500 27 280 361.83 0.774
40+ 3 14 25 0.560 33 242 448.66 0.539
363 4055 4183 0.969 2262 24613 26137.55 0.942

It was a tough year for the 28-year-olds and the over-35 crowd, but the 30- and 35-year-olds had a banner year, confounding prior trends of age 35 being a dramatic falloff. The 30-year-olds were bolstered by players like Nick Johnson and Victor Martinez rebounding from injury, while the 35-year-old cohort was strong in depth – Jeter, Tejada, Helton, Ichiro, Damon, Abreu, Casey Blake. That said, history still cautions to beware of 35-year-olds.
Then, the pitchers:

2009 Total
Age # WS EWSL % # WS EWSL %
21- 1 12 5 0.000 9 68 43.00 1.581
22 1 4 7 0.571 27 196 173.60 1.129
23 9 74 46 1.609 56 416 373.76 1.113
24 11 80 74 1.081 91 645 572.37 1.127
25 34 260 241 1.079 142 1001 910.40 1.100
26 29 182 163 1.117 164 1080 1002.20 1.078
27 29 139 187 0.743 156 1038 1131.56 0.917
28 25 179 222 0.806 162 1122 1178.30 0.952
29 17 85 113 0.752 155 999 1149.31 0.869
30 28 208 253 0.822 156 950 1123.40 0.846
31 23 97 147 0.660 132 812 983.47 0.826
32 20 154 161 0.957 104 649 837.46 0.775
33 11 54 89 0.607 82 434 633.30 0.685
34 14 111 99 1.121 70 373 485.63 0.768
35 8 29 29 1.000 52 235 343.17 0.685
36 7 45 38 1.184 46 264 292.17 0.904
37 4 17 27 0.630 37 240 291.33 0.824
38 3 13 17 0.765 37 247 310.00 0.797
39 6 33 51 0.647 27 197 228.33 0.863
40+ 7 32 55 0.582 62 430 594.34 0.723
287 1808 2024 0.893 1767 11396 12657.09 0.900

Tough year all around, with the rot setting in as early as age 27 – the dramatic falloff in pitchers in their late 20s is driven heavily by injuries – while the age 34-36 survivors, though few in number, prospered, though other than Chris Carpenter it was mostly low-expectations relievers.
Finally, the rookie adjustments:

Type of Player # in 2009 WS in 2009 # 2004-09 WS 2004-09 Rate
Everyday Players 6 44 58 629 10.84
Bench Players (Under 30) 18 92 62 251 4.05
Bench Players (Age 30+) 1 1 4 3 0.75
Rotation Starters 10 36 28 113 4.04
Relief Pitchers 4 21 15 86 5.73
TOTAL 39 194 167 1082 6.48

Not a whole lot of alteration to historical patterns there.