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Is floor percentage useful?

“Floor percentage is the fraction of a team’s or individual possessions on which there is a scoring possession.” Dean Oliver.

Example of a game:

Team  A 70 points
10/20 free throws
30/65 field goals
Team  B  80 points
10/20 free throws
30/65 field goals

Both teams have the same amount of defensive and offensive rebounds, turnovers, steals, blocs, fouls, assists etc. They have the same team possessions and the same floor percentage, but a different score.

The identical field goal percentage is split in:

Team A
30/60     2pointers
0/5        3pointers
Team B
20/45    2pointers
10/20    3pointers

The difference in the number of threes is the difference in the score.

Going on in this example with a little more detail:

The 10/20 free throws for the two teams are distributed in a different way.
Every player of team A misses his first free throw, but is successful in his second. 
The free throws of team B: 5 times 2/2 and 5 times 0/2.
The floor percentage for the losing team A is now    40/75  =  53.33 %.
The floor percentage for the winning team B is now 35/75  =  46.66 %.

Team B also has 5 extra chances to rebound offensively the missed FT and has 5 passive possessions. Those offensive rebound opportunities can make the floor percentage of the winning team B even worse, with a possible 35/80 = 43.75 %, but with the same winning score 70-80. Team A has 10 passive possessions in this extreme example.
The calculated floor percentage presented here is really fading away from the rating of points per possession. Is floor percentage useful?

The credit of an offensive rebound can only be translated in an active possession, the credit part of an offensive rebound cannot (never) be taken away, split or transferred to or from a field goal, or from or to a free throw.

There is never a credit competition between offensive rebounding and scoring, between Jordan and Rodman. On the contrary, offensive rebounding helps to increase the scoring numbers. Missing shots …helps to increase the offensive rebounding opportunities.
If you never miss, you can forget offensive rebounding. Scoring is the ultimate goal, offensive rebounding is an important offensive repairing tool to correct the missed shot in a new try for a goal. Scoring means more points. Offensive rebounding means more possessions to shoot.

There is only one good scientific way to put and evaluate the performance of all these factors together : evaluating the performance of the individuals with their team results.

Rodman closed the door for a box score evaluation of the individual performance, but is there another way?

Yes, there are other ways. We can take the team numbers (Chicago Bulls) and subtract the player’s numbers (Jordan or Rodman etc.). This door is not yet closed.
We have listed the season numbers of 1996 with the subtraction of the individual numbers on the right side and the “closed door“ numbers on the left.

2.6463 Rodman 1.0931
1.2837 Kerr 1.1076
1.1788 Kukoc 1.1120
1.1384 Jordan 1.1125
1.1199 Chicago 1.1199
1.1029 Wennington 1.1207
1.0585 Harper 1.1247
1.0120 Longley 1.1283
1.0583 Pippen 1.1337

These are only the offensive evaluation numbers of the performance of 8 Chicago players :  
=  points (team - player) / (possessions (team - player) - offensive rebounds (team - player))

The evaluation of the poorest team rest numbers are these of the better players.
Mathematically correct, but we do not welcome the “deviations”.
There is a “magnetic field” around the team numbers. The players with smaller
numbers are more affected and centred around the team numbers of Chicago.
They also feel the difference in sample of time and maybe also a difference in the quality
they play. The numbers of Jordan, Pippen and Rodman are interacting as heavyweights.

Rodman has even better numbers and Kerr cannot hold his high numbers in the finals of 1996.
With the basketball performance evaluations you have to deal with more.

We have to take care of another big problem: the interactions.
 We said this already in “conditions for evaluating”. “You need a good mix of line-ups to create and to spread the effect of the different interactions.”
With a motivated Rodman, Chicago is a different team. Without Rodman (or Jordan), all these unique Chicago players adapt or have to adapt. The results of this adaptation is completely different from the simple subtraction of the numbers of Rodman or Jordan.
The team will lose Rodman or Jordan, but not all their numbers, maybe less, maybe more. Some have a growing effect, other have a melting effect.

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