Age Limit stats: "Under 20's" vs. "Over-20 Rookies"

[Spurminator]

Here are some numbers to support the Age Limit discussion earlier today. I calculated Games, Minutes Per Game, and Efficiency Ratings for the following:

A) All players who were under 20 years old as of June 15, 1984
B) All 2004-drafted rookies not included in (A)

The numbers somewhat support the theory that more experienced rookies, whether by college or Euro-pro leagues, etc., are more able to contribnute immediately to the team. However, those against the Age Limit could point out that the data is so close it's almost negligible.

(EDIT: Cleaned up code a little bit)

Players born after June 15, 1984


Games MPG EFF/G
LeBron James 75 42.1 28.04
Dwight Howard 76 32.4 17.99
Josh Smith 68 26.8 12.55
Luol Deng 61 27.3 11.77
S. Livingston 25 25.5 11.2
Al Jefferson 65 14.9 8.38
Seb. Telfair 63 18.3 6.51
Trevor Ariza 75 17.1 6.43
Andris Biedrins 25 11.85 6.31
Travis Outlaw 53 12.2 5.85
J.R. Smith 70 23.6 5.51
K. Perkins 55 8.8 5.11
Kris Humphries 61 12.1 4.64
Jackie Butler 3 1.7 3.67
Maciej Lampe 31 8.8 2.39
Peter J. Ramos 6 3.3 1.67
Darko Milicic 33 5.4 1.26
Ha Seung-Jin 14 4.8 1
Pavel Podkolzin 5 2 0.4
Robert Swift 15 3.7 0.27
Ndudi Ebi 0 0 0
Dorell Wright 1 2 -3

Rookies born after June 15, 1984


Games MPG EFF/G
Emeka Okafor 69 35.9 18.48
Andre Iguodala 76 32.7 14.16
Josh Childress 74 28.7 13
Nenad Krstic 70 25.7 11.11
Ben Gordon 77 24.4 9.94
Matt Bonner 77 19.2 8.71
Jameer Nelson 73 19.2 8.61
Andres Nocioni 77 23.1 8.47
A. Varejao 49 15.7 8.35
Chris Duhon 77 26.3 8.26
David Harrison 43 17.7 7.28
Tony Allen 71 16.3 7.23
Viktor Khryapa 26 15.6 6.54
Devin Harris 70 15.4 6.27
Jackson Vroman 40 13.4 5.95
Royal Ivey 56 13 5.35
Rafael Araujo 54 12.3 5.3
Beno Udrih 75 14 5.17
Delonte West 34 13.2 4.91
B. Robinson 31 10.6 4.13
Donta Smith 33 10.7 4
Kirk Snyder 63 12.4 3.48
Antonio Burks 20 10 3.38
Sasha Vujacic 31 9.9 2.87
Kevin Martin 41 9.6 2.66
Lionel Chalmers 34 12.4 2.44
Justin Reed 20 4.4 2
Pape Sow 21 6.4 1.64
Luke Jackson 10 4.3 1.6
Andre Emmett 8 3.5 0.38

Under-20 Summary
Avg Games Played: 40
MPG: 13.9
EFF/G: 6.27
Players: 22
Players above median EFF (combined): 10

20-and-over Rookie Summary
Avg Games Played: 50
MPG: 15.9
EFF/G: 6.39
Players: 30
Players above median EFF (combined): 16


I'm probably missing some players that may be rookies this year but were drafted a previous year. I'm amazed that there seems to be no site with a one page reference for "rookies."

*Stats apply to all games prior to April 12, 2005

[jalbre6]

Good research, boss. Might wanna fix the born on stuff, though.

What's kind of wild is the higher ratings for the top 5 youngsters compared to the top five older guys. I wouldn't have guessed that.

[Cant_Be_Faded]

I suggest someone do a statistical independent 2 sample t-test on the efficiency ratings to see if they differ significantly at the 0.05 level.

[Cant_Be_Faded]

ok i just did a t-test, using conservative degrees of freedom (39), and going by efficiency ratings as means and number of games as n

t = 0.089
p value >>>0.200
conclusion: efficiency ratings do not differ enough to consider the true means are really different.

lol, im in a lame ass statistics class :lol

[Cant_Be_Faded]

just did another t-test, comparing minutes per game, and using players as n

using conservative degrees of freedom, there is a significant difference in minutes played at the 0.05 level.....

in fact p value was between 0.03 and 0.04

[Phenomanul]

just did another t-test, comparing minutes per game, and using players as n

using conservative degrees of freedom, there is a significant difference in minutes played at the 0.05 level.....

in fact p value was between 0.03 and 0.04


Which means that there is enough statistical significance between the two samples regarding minutes played, but not enough difference between their efficiencies.

Someone needs to point this stat out to Stern and Battier.

[spurster]

Am I the only one noticing "born after June 15, 2004"? I can certainly agree that drafting players less than 1 year old is a bad idea. :)

Not only that but "born after June 15, 2004" is in the heading for both lists.

[Spurminator]

Shut up, it was past midnight.

;)

[sickdsm]

One has to take into account that the draft class's weren't anywhere the same strength.

I think MPG is a more valuable statistic than effiencey though.

[Aggie Hoopsfan]

I don't think your comparison is legitimate unless you factor in all the players that fit the first category who were drafted but are no longer in the league.

You've got guys like Ebi who are obvious pro busts (at least until a few years away when they mature enough physically and mentally), and you've got guys like Leon Smith who aren't even in the league anymore.

[Cant_Be_Faded]

I don't think your comparison is legitimate unless you factor in all the players that fit the first category who were drafted but are no longer in the league.

You've got guys like Ebi who are obvious pro busts (at least until a few years away when they mature enough physically and mentally), and you've got guys like Leon Smith who aren't even in the league anymore.


yeah all valid suggestions

Some guys get cut fast

I think the real knock on comparing efficiency and minutes is that we don't know when those extra points or minutes came in trash time or game time.

[Spurminator]

I don't think your comparison is legitimate unless you factor in all the players that fit the first category who were drafted but are no longer in the league.

You've got guys like Ebi who are obvious pro busts (at least until a few years away when they mature enough physically and mentally), and you've got guys like Leon Smith who aren't even in the league anymore.

Unless I'm missing someone, none of the players who were drafted in 2003 and tendered contracts by the teams that drafted them fit that description. The ones who are still in the league, like Ebi and Perkins... and James... are included in the data.

Leon Smith was drafted in 1999. A lot of Draftees, college graduates included, have dropped out of the league since then.


I think the real knock on comparing efficiency and minutes is that we don't know when those extra points or minutes came in trash time or game time.

Over an 82 game period, everything should basically even out. If a player is only playing during garbage time, that would be reflected in his Games Played and Minutes Played. A player with 70 Games and 10 MPG is probably seeing a significant amount of real NBA court time.