Ranking NBA entry classes

[Mike G]

An entry class is a group of players making their NBA debut in a given year. It is usually but not always the year after they were drafted.
From b-r.com, I got players with at least 10 career VORP. Since 1974, there are almost 400 such players.
http://bkref.com/tiny/m6BsX
I added another 100 players with <10 VORP but >21 Win Shares.
Then, being lazy, I deleted all those players whose 'vorp careers' start in 1974; leaving 400+ "significant players", sorted by year of entry. Players starting in the ABA, 1975 and 1976, are included.
Sum of WS and VORP and summary career PER are listed, along with "top" players entering each year.

Code: Select all

From   VORP   WS    PER    players
1975   272   934   17.3   Moses, BJones, JDrew, MiJohnson, BKnight, Wilkes, MLucas, Walton
1976   198   585   16.7   AAdams, G Williams, Roundfield, D Thompson, Free
1977   193   646   17.3   Dantley, Parish, English, D Johnson
1978   292   989   15.9   Sikma, Mar Johnson, King, Maxwell, W Davis, Rollins, Ballard
1979   149   534   15.5   Cheeks, Theus, MThompson, MRRichardson

1980   254   673   18.6   Magic, Bird, Moncrief, Natt
1981   147   576   15.6   McHale, Laimbeer, Kiki
1982   287   993   16.1   Nance, Buck W, Isiah, Aguirre, Ainge, Blackman, Chambers
1983   228   678   16.6   'Nique, Cummings, Worthy, Lever, Pressey
1984   253   825   15.2   Drexler, D Harper, Rivers, D Ellis, B Scott, McCray

From   VORP   WS    PER    players
1985   524  1390   18.8   Jordan, Barkley, Stock, Hakeem, Thorpe, Perk, ARobertson, Kersey
1986   397  1229   17.2  Malone, Ewing, TPorter, Mullin, Schrempf, Oakley, ACGreen, Dumars
1987   252   694   15.6   Hornacek, Rodman, R Harper, Price, Daugherty, HotRod, McMillan
1988   301   935   16.5   Reggie, Pippen, HoGrant, KJ, M Jackson, McKey
1989   236   852   15.4   Hawkins, Strickland, Majerle, Richmond, Manning

1990   360  1035   16.9   D-Rob, Divac, TBug, Blaylock, Kemp, Mason, CliffR, Rice, NickA
1991   151   535   16.3   Payton, Coleman; Gill, Campbell, Elie  
1992   208   639   15.8   Mutombo, D Davis, S Smith, LJohnson, Brandon, K Anderson
1993   275   741   17.0   Shaq, Mourning, Horry, Laettner, Christie, Sprewell
1994   324   992   15.6   Webber, Cassell, PJ Brown, Penny, Kukoc, Outlaw

From   VORP   WS    PER    players
1995   288   766   16.2   Kidd, Hill, E Jones, Marshall, DArmstrong
1996   297   926   16.6   Garnett, Rasheed, Finley, B Barry, McDyess, Sabonis
1997   435  1215   17.5   Kobe, Allen, Iverson, Nash, BenW, Camby, Marbs, Shareef, JO'Neal
1998   216   655   19.1   Duncan, McGrady, Billups, Ilgauskas
1999   374  1158   17.5   Dirk, Pierce, Vince, RLewis, B Miller, Peja, Jamison, Bibby

2000   368   998   16.9   Marion, Brand, Terry, A Miller, Odom, B Davis, Francis, Artest
2001    98   318   15.4   Turkoglu, M Miller, Redd; K Martin, JCrawford
2002   349  1043   17.0   P Gasol, Kirilenko, Parker, Chandler, Battier, J Johnson, 
.                          G Wallace, Arenas, JRich, RJeff, Zach
2003   189   664   17.7   Ginobili, Boozer, Amare', Yao, Nene
2004   328   942   17.8   LeBron, Wade, Bosh, Carmelo, DWest

From   VORP   WS    PER    players
2005   261   799   16.8   Dwight, Iguodala, J Smith, Deng, AJefferson; KevMartin, Ariza
2006   198   641   18.0   Paul, D Williams, D Lee; Bogut, Granger, Amir, Calderon
2007   135   364   17.2   Millsap, Aldridge, Lowry; Rondo, Roy, Gay
2008   137   406   18.1   Durant, Noah, Horford; Conley
2009   149   391   18.8   Westbrook, M Gasol, Love; Batum, D Jordan, G Hill

2010   118   304   18.1   Harden, Curry; Lawson, Ibaka
2011    69   161   20.1   Griffin; Monroe, P George
2012    36    78   18.3   - Leonard, Irving
2013    22    57   22.0   - ADavis, Lillard.

Obviously these late years will have exponentially greater totals as time goes on.
Players listed are ranked by :
xyz = (VORP*WS*PER)^(1/3)
Showing those with career xyz > 25; and in later years (after the semicolon) xyz > 20

[Mike G]

Here are entry years ranked by Class xyz: The 8 to 16 players representing each year have had their WS, VORP, and PER summed; and xyz for that year is determined by the formula shown above.
M000 are thousands of minutes in the RS careers of the players of each entry year.
sum is the total of player xyz for each year of entry. Ranking by that total is sometimes different (rk2) than column 1 (xyz).

Code: Select all

xyz     yr    VORP    WS     PER    M000    sum   rk2
239    1985    524   1390    18.8    437    530     1
210    1997    435   1215    17.5    460    498     2
203    1986    397   1229    17.2    442    453     4
196    1999    374   1158    17.5    431    463     3
185    1990    360   1035    16.9    376    397    11

184    2000    368    998    16.9    398    430     7
183    2002    349   1043    17.0    392    439     5
176    2004    328    942    17.8    342    400    10
171    1994    324    992    15.6    436    436     6
167    1988    301    935    16.5    348    354    15

xyz     yr    VORP    WS     PER    M000    sum   rk2
166    1978    292    989    15.9    414    404     8
166    1982    287    993    16.1    418    403     9
166    1996    297    926    16.6    359    370    13
164    1975    272    934    17.3    354    390    12
153    1995    288    766    16.2    328    334    16

152    2005    261    799    16.8    316    364    14
151    1993    275    741    17.0    306    334    17
147    1980    254    673    18.6    206    280    23
147    1984    253    825    15.2    357    289    21
146    1989    236    852    15.4    369    319    18

xyz     yr    VORP    WS     PER    M000    sum   rk2
140    1987    252    694    15.6    280    304    19
139    1998    216    655    19.1    206    255    27
137    1983    228    678    16.6    270    295    20
132    2006    198    641    18.0    225    289    22
131    2003    189    664    17.7    235    276    24

129    1977    193    646    17.3    246    253    28
128    1992    208    639    15.8    247    271    25
125    1976    198    585    16.7    232    270    26
110    1981    147    576    15.6    215    222    29
109    1991    151    535    16.3    218    211    31

xyz     yr    VORP    WS     PER    M000    sum   rk2
107    1979    149    534    15.5    251    213    30
103    2009    149    391    18.8    129    211    32
100    2008    137    406    18.1    136    197    33
95     2007    135    364    17.2    139    187    34
87     2010    118    304    18.1    104    170    35

78     2001     98    318    15.4    156    141    36
61     2011     69    161    20.1     58    103    37
37     2012     36     78    18.3     26     53    38
30     2013     22     57    22.0     16     38    39

Note the higher PER in later years. Only elite players tend to be represented here. In years with lower PER (approaching 15.0), there are several players who just played a long time.

While the sample size we see in a year -- usually 10-12 players -- tends to give proportionate WS and VORP, there's wide disparity among players. Kevin Willis has career PER of 15.7, WS/48 = .102 -- above average player, right?
He's 39th in career minutes, has 82 WS -- and just 2.0 VORP. His career BPM is -1.8, or barely 'replacement level'.

Wayman Tisdale, with 45.7 WS and 15.7 PER has BPM = -2.0, and zero VORP. This zeroes out his xyz, as well.
John Paxson, Avery Johnson, and Sam Mitchell all have 25-35 WS and negative VORP; making their xyz negative, as well.

[Crow]

From your raw data I assume you can calculate player averages and an aging curve of productivity added in nth career year. Have the averages and increments of last 7-10 entry classes shown decline in one or both?

Where do people (including analytic draft model people) project this entry class will fall in first year and long term compared to other classes? Top third, middle or bottom? I am guessing middle toward bottom on first year and still middle at best longer but is just off the cuff guess.

[Mike G]

From your raw data I assume you can calculate player averages and an aging curve of productivity added in nth career year. ..

Nope. Just used b-r.com combined season search as referenced at top. To do 3- or 5-year summaries, one would have to get numerous pages, delete and shuffle player lines, etc. As much work as this, several times over.

I don't know that there's any value in studying how, for example, the Class of '95 developed relative to the Class of '05. But a study of how players in general mature over an interval, could be undertaken.

Having said that, it might be interesting to see how a rookie class rating (xyz or single measure) pans out to career rating. That 2003 rookie class was led by Yao, Nene, and Amare', none of whom have had long and great careers.

[Crow]

From pages like this http://www.basketball-reference.com/draft/NBA_1999.html the averages can be computed easily. Sum values and divide by 14 for this class.

Aging curves and changing aging curves would take a bit more work. Teams should do it. Affects value of first and second contract guys and decisions to keep them, year to year and what to pay them. Developmental payoff rates might be changing. Worth knowing imo, if in the biz at least.