APBRmetrics

schtevie · Joined: 18 Apr 2005 Posts: 414

Gabe, sorry that my reaction to the list of names you transcribed upset you. That wasn't my intention. Anyway, the Celtics are in the Finals. All is right in the universe again. Be happy!

Let me begin with a specific reply to what unnerved you, and then let's stand back and look at the big picture. You are looking to poke a hole in my argument that replacement value is a terrible, horrible, no good, very bad idea (as a relevant opportunity cost for NBA transactions). Fine. But I explicitly allowed for the fact that it wouldn't surprise me if somewhere in the second round such relevance would obtain.

That the transaction log "gave me a headache" was by no means a knock on http://www.prosportstransactions.com/ (and it is not proper of you to allege that). The site is a great resource of raw information. My difficulty had to do with the sifting through all the names, teams, and dates to identify what would be a relevant piece of evidence, namely: a transaction where a known replacement player was traded, straight up (or as a clear subset of a larger transaction) for a draftee. (I emphasize the word 'known' because that is the essence of the argument. If ex post, one sees that a young player, say, traded for a draft pick ends up to be a replacement level player, that is evidence of nothing.)

That you either did not try to find such a transaction, or perhaps tried and failed, in this task, tells me that it was a bit headachey for you too. And again, I would be happy to learn of any such non-holes in my argument.

The draft aside, I simply don't understand your focus on trying to establish whether or not I am making categorical distinctions between "starters" and "replacements". Is that to poke a another hole in my argument? If so, I am missing the jab, never mind the hypothetical chink in the armor?

If you think that the concept of a replacement level player is in any important way relevant to assessing the value of a starter in the league, please make the argument.

gabefarkas · Joined: 31 Dec 2004 Posts: 1313 Location: Durham, NC

First, let's consider the case where there really is a dichotomy, with two distinct groups of players. Here, the importance of VORP should be intuitively obvious. It would be the ultimate measuring stick to use when considering which of the "warm bodies" to add to your team. In other words, a difference between an APM of -7.2 and -8.4 isn't going to be very insightful, but VORP probably will be.

Second, consider the case of a continuum. Start with what you wrote:
"Replacement level players are going to be on a team as a class, independent of the existence of starters, independent of players 6 through 10".
Next, what DSMok1 wrote:
"If, during the season, LBJ is hurt and lost for the season, who takes his place on the roster? That is his replacement. The margin between LBJ and whoever took his place on the roster is the value of LBJ. Thus VORP."

Together, I think these confirm the idea of a continuum. That said, I'll start simple and say that I think these imply a trickle-up effect, where VORP is important because eventually that loss of talent finds its way into the starting lineup.

If this doesn't make sense, let me know, and I'll try to come up with a more detailed explanation.

gabefarkas · Joined: 31 Dec 2004 Posts: 1313 Location: Durham, NC

I saw this article, and it reminded me of the Replacement Level discussion we were having, so I wanted to share it with the group:
http://sabermetricresearch.blogspot.com/2010/12/replacement-level-talent-vs.html