Explanation of SANZ Player Ratings System

DISCLAIMER: These ratings are limited to data obtained from boxscores and cannot capture intangibles such as screens, leadership, boxing out, shot that won the game, etc. The "role" label attempts to address this by acknowledging there must be a reason why the coach gives lots of playing time to an apparently underperforming player.

SANZ - Sports and Numbers Z-Rating

SANZ ratings represent the relative contribution a player makes to the team statistics. That is, these ratings cannot be used to compare the performance of a player on this team versus players on another team. This is because the ratings incorporate the use of z-scores, or "grading on a curve." The only people in that curve are the players on this team.

Note: In calculating SANZ ratings, I exclude players who have played less than 20 cumulative minutes all season.  In calculating eSANZ ratings, I exclude players who have played less than 8 adjusted minutes all season (equates to a player having played 8 minutes in the most recent game against an opponent as good or better than his team).  These exclusions are made to avoid unreasonable extrapolations.

Players are given z-scores in all three shooting categories as well as all other boxscore categories (O-REB, D-REB, T-REB, AST, STL, BLK, TO, PF). Shooting category z-scores are determined using a formula that measures how well and how often a player shoots. Players that shoot the team average would receive a rating of 0 for that specific category. A player who shoots well above the average but not very often may receive a lower rating than a player who shoots slightly above team average but shoots all the time.

For other boxscore categories, each category z-score takes into account the per-game and per-minute averages. This is in recognition of the fact that some players perform well in their brief minutes, but they are not contributing as much to the game as those who play more minutes and contribute more each game.  Although the ratings are meant to capture efficiency, they are also to serve as a guide to who has actually made the contributions.

SANZ ratings are then calculated by taking the z-scores in each of these categories (2FG, 3FG, FT, O-REB, D-REB, T-REB, AST, STL, BLK, TO, PF) and weighing them according to the player's position:

• Small = Guard 6'3" or smaller
• Combo = Any Guard at least 6'4", or any Forward 6'7" or less, or any player listed as "G/F"
• Big = Center or any Forward 6'8" or taller that doesn't meet criteria for Combo

Thus, smalls are weighed more heavily in categories like AST and STL, while bigs' ratings more heavily emphasize BLK, rebounding categories, etc.

"Rotation Identifiers" are used as a guide to gauge team quality depth.  These labels are not meant to be an insult to anyone -- just an easy-to-remember way of categorizing:

• Baller = Plays at least 5 mpg and plays at about average level or better (formerly called "Regular")
• Role = Plays at least 15 mpg but plays significantly below averag
• Misfiring = Plays 5-15 mpg, but plays significantly below average (formerly called "Dud")
• Benchwarmer = Plays < 5 mpg (formerly called "Scrub")

eSANZ - "Enhanced" SANZ

Recently, I've enhanced the system to reflect two important adjustments:

1. Games that are more recent are weighted more heavily
2. Games against teams that are equal or better in strength (determined by power ratings) are weighted more heavily than games against weaker teams.

To make the two adjustments noted above, each game is given a weight (between 0 and 1) that is derived from the two factors mentioned above. The stats from that game are then multiplied by the weight factor and added up to provide an "adjusted cumulative boxscore" for the season. One of the figures from this boxscore is "adjusted minutes per game," which factors in how I assign a "rotation identifier" to each player when using eSANZ Ratings. I use the same criteria as regular SANZ, but I subsitute "adjusted mpg" for regular "mpg" figures.

• Baller = Plays at least 5 adjusted mpg and plays at about average level or better
• Role = Plays at least 15 adjusted mpg but plays significantly below average
• Misfiring = Plays 5-15 adjusted mpg, but plays significantly below average
• Benchwarmer = Plays < 5 adjusted mpg

Abbreviations and Terms

Note: When I refer to these categories, I am usually talking about the z-score for that category (i.e., Player A has a good STL rating = Player A's z-score for steals is significantly above zero)

• 2FG - A special rating for 2-point field goal shooting, derived from a formula that measures how well and how often a player shoots
• 3FG - A special rating for 2-point field goal shooting, derived from a formula that measures how well and how often a player shoots
• FT - A special rating for freethrow shooting, derived from a formula that measures how well and how often a player shoots
• O-REB - Offensive Rebounding
• D-REB - Defensive Rebounding
• T-REB or TOT - Total Rebounding
• AST - Assists
• STL - Steals
• BLK - Blocks
• TO - Turnovers
• PF - Personal Fouls
• SANZ - Sports and Numbers Z-Rating
• eSANZ - Enhanced SANZ
• Z-score - A statistical term used to measure how far a data point is from the mean of the population (i.e., how much better or worse than average is a particular statistic).  Z-scores usually range from -3 to +3.  It is rare to see scores outside this range.
• MPG - Minutes per game
• Adjusted Cumulative Boxscore - A boxscore representing season totals for all players after multiplying each game's stats by a weight factor that takes into account how recent the game was and the quality of the opponent
• Adjusted MPG - Minutes per game from the "adjusted cumulative boxscore"

Email this page to your friend

Copyright © 2006 Sports and Numbers. All Rights Reserved.  Terms of Use  Privacy Policy