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February 5, 2004

Winter Leagues, Redux

What Can We Learn About Players' Futures?

by Clay Davenport

In the first part of our winter leagues study, we looked at what the player performances said about each league's level of quality. In Part II, we'll look at what player performance in these leagues say about a player's future.

The first thing to remember is that winter league statistics are forged in short-season leagues, so any stats represent a small sample relative to regular-season play. The highest AB+BB totals in these leagues over the last few years have been:

Arizona Fall League     Drew Henson, 2002       166
Dominican W.L.          Eddy Garabito, 2002     217
Puerto Rican W.L.       Alex Cora, 2001         223
Venezuelan W.L.         Alex Sanchez, 2000      262
Mexican Pacific L.      Darrell Sherman, 2003   297

In order to test changes in player performances, I created a test set of players who met the following criteria:

  • They had at least 250 plate appearances (AB+BB) in the regular season before playing winter ball;

  • They had at least 75 plate appearances in winter ball;

  • They had at least 250 plate appearances in the regular season after winter ball.

This gave me 391 players, or rather 391 sets of three player-seasons. All of the statistics were translated, using the difficulty ratings in the previous half of the article. From the summary statistics, it is apparent that they performed similarly as a group in each of the subsets:

  • In the regular season before winter ball, players averaged 332 outs and a .230 EqA;

  • In winter ball, they averaged 99 outs and a .231 EqA;

  • In the following regular season, they averaged 315 outs and a .231 EqA.

You would expect that the correlation between player EqAs in the regular seasons would be stronger than the correlation between either regular season or winter ball, simply because the smaller number of PA from winter ball increases the variability in player performance. That is, in fact, exactly what you find. The correlations are:

  • Between the two regular seasons .55

  • Between prior season and winter .29

  • Between winter and next season .33

Next, I sorted the players based on the difference between their equivalent runs per out in the prior regular season and in winter ball. I am using equivalent runs per out, not equivalent average; EqA is nice for display purposes, but it isn't linear, and that is important for this study. The question at hand is, if a player improves between the regular season and winter ball, does that spill over to the following season?

The answer to that is a qualified yes--it does, if the difference is big enough.

To give people an idea of how big the differences are, a player with a .260 EqA (league average, by definition) will generate .172 equivalent runs per out (EqA, raised to 2.5 power, times 5 = .172). If he improved his offensive level by .025 EqR/out, his EqA would increase to .274. Improve by .050 EqR/out, and EqA is up to .288; improve by .075, and our formerly average hitter is up to .300. Declines of .025, .050, and .075 would reduce our average hitter to EqAs of .244, .227, and .207.

Change in EqR/out       N       Nsame   Percent Chance
>= .075         22      16      73      .992
.050 to .0749   30      21      70      .992
.025 to .0499   56      30      54      .748
0 to.0249       77      40      52      .676

-.025 to -0.01  87      43      49      .500
-.050 to -.251  60      35      58      .922
-.075 to -.051  40      30      75      .9997
<= -.075        19      16      84      .9996

"Change in EqR/out" is winter league EqR/out minus regular season EqR/out. N is the number of player-seasons within the range. Nsame is the number of players whose following season's EqR/out changed in the same direction as their winter league EqR/out, although not necessarily by the same amount. Percent is 100*Nsame/N. "Chance" is the cumulative binomial probability distribution for Nsame and N, assuming a 50/50 chance for Nsame; the closer chance is to 1, the more likely this is a real effect, and not just random dumb luck.

Players whose winter league EqR/out scores improved by at least .05 EqR/run over the prior regular season had a 71% chance of having a better EqR/out (and hence a better EqA) in the following regular season than in the previous one. Players whose winter EqR/out dropped by .05 or more had a 78% chance of having a worse EqR/out (worse EqA) than in the previous year. Taken in total, players whose EqR/out changed by .05 or more are three times as likely to see their regular season EqA change in the same direction as their winter league performance. The average change was about one-fourth the winter league change.

Forty players improved their EqR/out by at least .050 points in 2003. In the list that followed, I've given the player's organization (as of 2003), the winter league he played in, his change in EqR/out, his combined 2003 EqA, and his "expected 2004 EqA," defined as 2003 EqA plus one-quarter the change in EqR/out.

                                   
                                                   2003    Exp 2004
                                           Delta   EqA     EqA
 1:     Lou Lucca          Mex     PRL     0.146   0.223   0.248 
 2:     Luis Figueroa      Sea     PRL     0.142   0.218   0.245 
 3:     Richard Lewis      Atl     AFL     0.136   0.196   0.225 
 4:     Emil Brown         Mex     MPL     0.122   0.257   0.275 
 5:     Hiram Bocachica    Det     PRL     0.097   0.223   0.240 
 6:     Victor Valencia    Cle     VWL     0.096   0.22    0.237 
 7:     Omar Infante       Det     VWL     0.092   0.204   0.223 
 8:     Julio Ramirez      Ana     DWL     0.089   0.214   0.231 
 9:     Jason Dubois       ChC     AFL     0.088   0.238   0.252 
10:     Rudy Pemberton     Mex     MPL     0.088   0.222   0.238 
11:     Tom Evans          Mex     VWL     0.084   0.196   0.214 
12:     Luis Garcia        Cle     MPL     0.083   0.189   0.206 
13:     Luke Scott         Cle     AFL     0.078   0.224   0.238 
14:     Luis Rivas         Min     VWL     0.077   0.242   0.254 
15:     Jonny Gomes        TB      AFL     0.074   0.236   0.248 
16:     Ricardo Saenz      Mex     MPL     0.074   0.209   0.224 
17:     Scott Hairston     Ari     AFL     0.073   0.217   0.229 
18:     Luis Lopez         Oak     PRL     0.073   0.214   0.228 
19:     Papo Bolivar       StL     VWL     0.061   0.213   0.225 
20:     Carlos Hernandez   Hou     VWL     0.061   0.168   0.184 
21:     Cody McKay         Cin     DWL     0.058   0.201   0.213 
22:     Pablo Ozuna        Col     DWL     0.058   0.2     0.212 
23:     D'Angelo Jimenez   Cin     DWL     0.056   0.261   0.269 
24:     Luis Arredondo     Mex     MPL     0.055   0.204   0.216 
25:     Donzell McDonald   Atl     PRL     0.055   0.229   0.238 
26:     Jorge Sequea       Tor     VWL     0.055   0.229   0.238 
27:     Carlos Valderrama  SF      VWL     0.055   0.215   0.225 
28:     Luis Gonzalez      Cle     VWL     0.054   0.236   0.245 
29:     Juan Sosa          Phi     DWL     0.054   0.202   0.212 
30:     Mike Vento         NYY     AFL     0.054   0.242   0.251 
31:     Miguel Flores      Mex     MPL     0.053   0.199   0.210 
32:     Carlos Maldonado   CWS     VWL     0.053   0.214   0.224 
33:     John Pachot        SF      PRL     0.053   0.199   0.210 
34:     Izzy Alcantara     Mex     DWL     0.052   0.236   0.245 
35:     Juan Diaz          Bal     PRL     0.052   0.24    0.249 
36:     Adam LaRoche       Atl     PRL     0.052   0.252   0.260 
37:     Joe Espada         SF      PRL     0.051   0.189   0.201 
38:     Omar Garcia        Mex     PRL     0.051   0.238   0.246 
39:     Mario Santana      Mex     MPL     0.051   0.167   0.181 
40:     Raul Nieves        SD      PRL     0.05    0.176   0.191 

By the same token, there were 39 players who lost .050 EqR/out or more.

                                                     2003    Exp 2004
                                             Delta   EqA     EqA
 1:     Robert Machado       Bal     VWL     -0.122  0.275   0.258 
 2:     Justin Morneau       Min     PRL     -0.104  0.248   0.230 
 3:     Jolbert Cabrera      LA      VWL     -0.103  0.268   0.252 
 4:     Dallas McPherson     Ana     AFL     -0.102  0.246   0.228 
 5:     Craig Monroe         Det     PRL     -0.093  0.261   0.246 
 6:     Colin Porter         Hou     AFL     -0.093  0.264   0.249 
 7:     Jeremy Ware          Mon     VWL     -0.086  0.226   0.210 
 8:     Noah Hall            Mon     VWL     -0.083  0.252   0.239 
 9:     Armando Rios         CWS     PRL     -0.08   0.238   0.223 
10:     Roberto Zambrano     Mex     VWL     -0.074  0.248   0.235 
11:     Tony Alvarez         Pit     VWL     -0.072  0.256   0.245 
12:     Jon Knott            SD      AFL     -0.07   0.246   0.234 
13:     Santiago Perez       Cin     DWL     -0.069  0.23    0.217 
14:     Andy Abad            Bos     DWL     -0.067  0.254   0.244 
15:     Jamie Burke          CWS     DWL     -0.065  0.252   0.241 
16:     Lorenzo Buelna       Mex     MPL     -0.061  0.227   0.216 
17:     Pete Castellano      Mex     VWL     -0.06   0.24    0.231 
18:     Noe Munoz            Mex     MPL     -0.06   0.241   0.229 
19:     Koyie Hill           LA      DWL     -0.059  0.216   0.204 
20:     Terrmel Sledge       Mon     PRL     -0.059  0.277   0.268 
21:     Gabby Martinez       TB      PRL     -0.058  0.254   0.244 
22:     Abraham Nunez        Pit     DWL     -0.058  0.231   0.221 
23:     Anthony Sanders      CWS     VWL     -0.058  0.224   0.212 
24:     Carlos Leon          Bos     VWL     -0.057  0.218   0.209 
25:     Luis Rodriguez       Min     VWL     -0.057  0.228   0.217 
26:     Chad Santos          KC      AFL     -0.057  0.218   0.206 
27:     Ron Belliard         Cle     DWL     -0.055  0.246   0.237 
28:     Donald Kelly         Det     AFL     -0.054  0.226   0.216 
29:     Franklin Gutierrez   LA      VWL     -0.052  0.231   0.221 
30:     Carlos Villalobos    Mex     MPL     -0.052  0.255   0.245 
31:     John Gall            StL     MPL     -0.051  0.255   0.247 
32:     Felix Jose           Ari     DWL     -0.051  0.264   0.256 
33:     Dave Krynzel         Mil     AFL     -0.051  0.215   0.204 
34:     Donny Leon           ChC     PRL     -0.051  0.241   0.232 
35:     Mario Valdez         SD      MPL     -0.051  0.239   0.230 
36:     Manuel Velez         Mex     MPL     -0.051  0.212   0.203 
37:     Jimmy Alvarez        Tor     DWL     -0.05   0.227   0.218 
38:     Treni Hubbard        ChC     MPL     -0.05   0.254   0.246 
39:     Ramon Santiago       Det     DWL     -0.05   0.219   0.210 

For many of the players on these lists, their winter league performance really indicates nothing more than a return to form following an unusual regular season. Robert Machado, for instance, hit for a .227 EqA in 2001 and 2002 before busting out to .275 in 2003. His failure to hit in the Venezuelan league is hardly surprising, any more than the suggestion that he'll drop in 2004. Virtually every player on the down list (all but four) had a 2003 EqA that was higher than their 2001-03 average, itself a compelling reason to expect declines in 2004; the winter league results just add icing to the sweet rolls.

Similarly, 30 of the 40 players on the up list were coming off sub-par 2003 seasons. Some of the interesting names that were NOT coming off sub-par 2003s were:

Luis Rivas, who hit for his normal .242 EqA last year, but stuck a .287 in Venezuela.

D'Angelo Jimenez, whose .261 last year was well above the .249 he hit in 2001-02, went out and hit for a .292 EqA in the Dominican. BP has been high on him for years; could this be the year he returns the favor?

Adam LaRoche hit for a .218 EqA in 2001-02, as a first baseman in the Braves farm system. Last year he hit .247 at Double-A, raised that to .256 after being promoted to Triple-A, and took that to .282 in Puerto Rico. The winter league numbers suggest that last year's improvement was real, and that he could be a viable first baseman in the majors.

Related Content:  2003,  AFL

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