- --- In APBR_analysis@y..., "Mike Goodman" <msg_53@h...> wrote:
> --- In APBR_analysis@y..., harlanzo@y... wrote:

before

> > I am just curious about theory of minutes and dilution. I assume

> the

> > theory is that if a player's minutes dropped from the season

> > this is an indication that better players have come in to take

his

> > missing minutes. Thus the player who loses his minutes (from the

...

> > season before) occupyies the lower niche which creates a chain

> > reaction of other lower niches eventually dumping lower rung

> players

> > out of the league. THe end result of this is a higher

> concentration

> > of talent. Is this the correct assumption?

>

> We could assume, in a large sampling of players, there are

always

> about as many guys in decline as there are in ascension. And as

many

> good and average guys are entering the league as are retiring. If

then

> the concentration factors I have calculated are not equal to 1,

> there is either a net influx, or a net decline in talent

So a concentration factor > 1 means a net influx of talent? I think

> concentration.

> In theory.

that is what this all means. (Please correct me.) Actually the

concentration factor is a measure of net influx of talent, but not

dilution. Right? Getting a sense of dilution would mean comparing

the concentration factor increase to the increase in the number of

teams or the number of players. So the 2.85 factor over the last 50

years (when the league has gone from 10 teams to 29) means that

talent isn't all that diluted (2.85/2.9 ~1). It should have gone up

by a factor of 2.9 to keep up with the number of teams. On the other

hand, the number of players you are calculating this for went from 59

to 271, an increase of 4.5. So maybe it's diluted a lot (2.85/4.5).

I'm not sure which is the more relevant comparison.

I hope I'm right in my interpretations because, with this

understanding, I really do think you have something there. And I

wasn't sure there was a way to measure dilution. So simple yet so

apparently reasonable.

What players do you calculate the values for? Do you think we need

to correct for the number of games played, too (which change from

year to year, esp. early on)?

Dean Oliver

Journal of Basketball Studies - --- In APBR_analysis@y..., "Mike Goodman" <msg_53@h...> wrote:
> Responding to one of my own posts, again.

using

> I went ahead and tabulated the careers of some 1500 players,

> seasons spent with a single team. I have broken them down by career

Mike --

> length, from single-season careers to a 17+ year group.

> The 2nd and 3rd columns are the minutes played as rookie, and in

> final season.

>

> career avg. minutes

> length season annual decline

> ----- ----------- ----- --------------

> yrs. # first last net min. pct.

> 1 326 (500) (500)

> 2 156 685 561 -123 123 .180

> 3 129 873 626 -247 124 .142

> 4 93 916 688 -229 76 .083

> 5 76 1032 678 -354 88 .086

> 6 65 1150 784 -367 73 .064

> 7 86 1368 660 -709 118 .086

> 8 78 1415 734 -681 97 .069

> 9 96 1266 953 -313 39 .031

> 10 106 1448 912 -537 60 .041

> 11 92 1393 983 -410 41 .029

> 12 70 1534 1020 -513 47 .030

> 13 57 1779 1101 -678 57 .032

> 14 42 1734 1030 -704 54 .031

> 15 24 1436 1053 -383 27 .019

> 16 19 1881 1037 -844 56 .030

> 17+ 16 1997 480 -1516 89 .044

> __________________________________________

> 7.7 1531 1240 805 -435 65 .052

I think all this work with minutes is very interesting. Not precisely

sure what to make of it either, but it _seems_ relevant and

informative. (Maybe for doing something like James' career projection

stuff...)

For instance, it's interesting that players with longer careers never

fall to the level of 2 year players -- in terms of minutes. That

probably means that they are still better than the 2 year players even

after 16 years in the game.

Another way to look at the data would be to calculate the minutes for

players in their peak year and what year that typically was.

Calculate a decline rate in minutes per year from the year of peak.

I'm guessing that the peak minute year flatterns out at about 5 years,

based on the typical assumption that players' careers peak at age

27-28.

Dean Oliver

Journal of Basketball Studies