Let me start this off by saying this: I enjoy the information that advanced statistics provide, but I’m not here to indulge the belaboring of their usage. Beyond now, I won’t laud their merits nor will I condemn those who do not appreciate or care for their applications. I will reference them in my posts, as do several others on this board. Also, I will encourage you, now and only now, to embrace the enlightenment. THESE STATS ARE NOT BAD. They’re just different from what most of us are used to.
As they say, you can lead a horse to water, but you can’t make it drink. It’s entirely your prerogative.
Further, I admittedly lack the mental capacity to TRULY understand how to get all these numbers. I struggle with my times tables (Really? No, not really) so attempting to follow some of the calculations used to get them is a waste of time. I understand the overall principles, and that’s all I really need. Therefore coming to me for further explanations or deliberations of these numbers or formulas is, also, a waste of time. I don’t mean to be rude — just trying to save us all from such fruitless endeavors.
This, simply, is a reference point and brief explanation for those, including myself, who may be somewhat new to this way of interpreting information. It’s meant to be a scrolling mini-rolodex of terms to help you get your footing in this crazy, mixed-up world of advanced statistics.
The gist of these numbers, relating to basketball, is fairly simple. Traditional stats (FGM, PPG, AST, STL, BLK, etc…) are affected by the tempo at which the game is played. Think about it it terms of possessions and efficiency. Teams that play at a quicker pace may have deceptively inflated numbers. More possessions, more field goals, more points. But, that may not, necessarily, equate to a better or more efficient offense. We’re just leveling the playing field, looking at things based on an equal and unequivocal platform — typically one hundred (100) possessions — as opposed to the traditional, but variable, “per game” measurements. Per-chance and per-opportunity, instead of per-game. Tempo-free numbers, as it were.
The following is a compilation of stuff from several different places (Basketball-reference.com; kenpom.com; the Athlon Sports article found here that Zack referenced in his latest 15 numbers thread; as well as a few other insightful pieces found here and here) augmented and garnished with my own tidbits hither, thither and yon. It’s not all-encompassing, so I will add to it as needed. Your input and suggestions are welcomed and encouraged.
- Offensive Rating (ORtg) or Offensive Efficiency: How many points a team scores per 100 possessions.
- Defensive Rating (DRtg) or Defensive Efficiency: How many points a team allows per 100 possessions.
By measuring teams at an equal mark of 100 possessions, both of these stats eliminate the pace of play. They are the basis for judging how efficiently a team operates on offense and defense.
THE FOUR FACTORS — Dean Oliver’s key components for an efficient basketball team. Over time, teams that win tend to beat their opponents in these four categories. Oliver referred to them as the Four Factors of Basketball Success. They are ranked in order of importance, as follows.
1.) Effective Field Goal Percentage (eFG%): A shooting percentage that accounts for the added value of a 3-point shot. All field goals do not count the same, so why should they be measured as so? Big men who score close to the basket will have similar FG and eFG percentages, while guys who hit a lot of 3s will see a bump in the eFG numbers.
2.) Turnover percentage (TO%): The number of turnovers per 100 possessions. A team won’t be efficient if it gives away possessions.
3.) Offensive Rebound Percentage (ORB%): Measures the number of a team’s own missed shots that it collects. For a player, the percentage of rebounds he collects of those available to him. Gives the team more chances to achieve the ultimate goal of putting the ball in the basket.
4.) Free Throw Rate: Just getting to the line is an advantage, so it’s measured as FTA/FGA. There is no defense to account for and thus no chance to turn the ball over. Generally speaking, more FT attempts, more free points.
- Assist Rate (ARATE): Pomeroy lists this as the value of A/FGM.
- Block Rate (%BLK): Blocked shots/2PA.
- Steal Rate (%STL): Steals/defensive possessions.
- True Shooting Percentage (TS%): Another measure of shooting efficiency. Differs from eFG% in that it takes into account a player’s FT shooting percentage. Pomeroy’s exact definition: throws in trips to the line and converts it to a shooting percentage that approximates what 2-point percentage a player would need to have to score the points he produces on all of his shooting attempts
All of the above stats (except Defensive Rating) can be found based on an individual player’s performance as well as for each team. When going from “by team” to “by player,” the parameters are adjusted, and only account for that player’s time on the floor. The following are stats limited to single player qualifications only.
- Percentage of Possessions Used (%POSS): This percentage assigns credit of blame to a player when his actions result in the end of a possession e.g., missing a shot not rebounded by the offense, committing a turnover or making a shot. Often referred to as a player’s “usage rate.” Pomeroy notes that a higher percentage here does not mean the player is necessarily better, just more involved in the offense.
- Percentage of Possible Minutes Played (%MIN): I think this one pretty much stands on its own.
- Percentage of Shots Taken (%Shots): The percentage of a team’s shots taken while that player is on the floor. Similar in principle to usage rate or %POSS.