ttam68

03-25-2009, 05:52 PM

The idea behind Value Added is to take the difference between a given player's performance and that of a "replacement level" talent -- the type of guy who might be sitting at the end of a team's bench, or perhaps in Sioux Falls -- and multiply that difference by the number of minutes that player played. The result shows, theoretically, how many number of points the player added to his team's bottom line on the season.

VA is very useful for award voting in particular, because it allows us to compare players with disparate production and minutes -- say, one player who was brilliant in 60 games and another who was merely good but played all 82 -- and figure out which performance was more productive.

Now for the nitty-gritty.

"Replacement level" is a common term in sports analytics for the level of talent readily available to be picked up off the scrap heap. In NBA terms, it's either a minimum contract guy at the end of the bench or some other team's bench, a veteran off the free-agent scrap heap or a call-up from the D-League.

Nonetheless, analyzing several years of data and looking closely at players who played less than 500 minutes in a season reveals a pattern. The average PER for a "replacement level" player in the NBA is about 11.0, and it varies by position. Power forward is the most replaceable position, with an average replacement level PER of 11.5; the two wing positions are the least, at 10.5 each; point guards, at 11.0, and centers, at 10.6, fall somewhere in between.

Knowing the "replacement level" value at a given position, we can take a player's PER and minutes played and use it to calculate his VA. Chris Paul, for example, has played 2,470 minutes with a PER of 30.06 through Tuesday's games. Since the average replacement level PER for a point guard is 11.0, we take the difference (30.06-11.0) and multiply by his minutes played, returning a product of 47,078.2.

There's one more step. We want VA to mean something, and in this case we want it to be the approximate number of additional points the player has been worth to his team, over the course of the season, relative to a replacement level player. To get to Point A from Point B requires us to divide the result by 67. Yes, 67. Sorry, that's what works. (If you're curious, a point of PER over the course of 2,000 minutes is worth about 30 points to a team, meaning that one point of PER over one minute is worth 1/67th of a point.)

So what we end up with is the formula:

VA = ((Minutes * (PER -- Position Replacement Level)) / 67)

Where Position Replacement Level = 11.5 for power forwards, 11.0 for point guards, 10.6 for centers, and 10.5 for shooting guards and small forwards.

http://sports.espn.go.com/nba/columns/story?columnist=hollinger_john&page=PERDiem-090325

I don't see how he's answering critics of his PER considering this is just a modified form of PER. He still leaves out many elements ignored by PER, and has only really added minutes.

VA is very useful for award voting in particular, because it allows us to compare players with disparate production and minutes -- say, one player who was brilliant in 60 games and another who was merely good but played all 82 -- and figure out which performance was more productive.

Now for the nitty-gritty.

"Replacement level" is a common term in sports analytics for the level of talent readily available to be picked up off the scrap heap. In NBA terms, it's either a minimum contract guy at the end of the bench or some other team's bench, a veteran off the free-agent scrap heap or a call-up from the D-League.

Nonetheless, analyzing several years of data and looking closely at players who played less than 500 minutes in a season reveals a pattern. The average PER for a "replacement level" player in the NBA is about 11.0, and it varies by position. Power forward is the most replaceable position, with an average replacement level PER of 11.5; the two wing positions are the least, at 10.5 each; point guards, at 11.0, and centers, at 10.6, fall somewhere in between.

Knowing the "replacement level" value at a given position, we can take a player's PER and minutes played and use it to calculate his VA. Chris Paul, for example, has played 2,470 minutes with a PER of 30.06 through Tuesday's games. Since the average replacement level PER for a point guard is 11.0, we take the difference (30.06-11.0) and multiply by his minutes played, returning a product of 47,078.2.

There's one more step. We want VA to mean something, and in this case we want it to be the approximate number of additional points the player has been worth to his team, over the course of the season, relative to a replacement level player. To get to Point A from Point B requires us to divide the result by 67. Yes, 67. Sorry, that's what works. (If you're curious, a point of PER over the course of 2,000 minutes is worth about 30 points to a team, meaning that one point of PER over one minute is worth 1/67th of a point.)

So what we end up with is the formula:

VA = ((Minutes * (PER -- Position Replacement Level)) / 67)

Where Position Replacement Level = 11.5 for power forwards, 11.0 for point guards, 10.6 for centers, and 10.5 for shooting guards and small forwards.

http://sports.espn.go.com/nba/columns/story?columnist=hollinger_john&page=PERDiem-090325

I don't see how he's answering critics of his PER considering this is just a modified form of PER. He still leaves out many elements ignored by PER, and has only really added minutes.