Developing a Rating System for SOM Hoops

by Dave Little

Shooting

Shooting Ratings

Shooting ratings are based upon the assumption that the shot card will be consulted 10 times per game. There are two reasons for this assumption: (1) Each team will have roughly 100 possessions per game. Discounting turnovers and offensive rebounds (which will be analyzed separately), this means 20 shots per position player. One-half (3/6) of these results will come from the shot card, one-third (2/6) from the opponents' team defense card, and 1/6 from the opponents' X-column; (2) The action deck will provide each position with 7 shots per game. Additional shots will come from passing cards and the "inside/outside" and "switch" cards in the action deck.

Players with * ratings will receive extra shots from their teammates' passing cards and from the action deck. This accounts for roughly 2 extra shots per game for each star. The distribution of shots (inside, outside, penetration) is determined by the "Shooting Tendency" rating, and is highly dependent on the preferences of the coach. There is a slight bias in favor of outside shots over penetration shots due to the presence of action deck cards which specify, "Outside shot only for player positioned outside". The calculations for shot columns are based upon the following ratios:

Inside Player: 80% I / 10% O / 10% P
Outside Player:
*****: 80% P / 20% O
****: 50% P / 50% O
***: 60% O / 40% P
**: 70%O / 30% P
*: 80% O / 20% P

Each shot column consists of 36 chances. I will assign values for each chance based upon points per shot. The value system for shot results is as follows:

X - 2 points
O - 1 point (assuming 1/2 of all shots are open)
F(2) - 2 * FT%
X+F(1) - 2 + FT%
T - minus 1 (loss of possession)
R - minus 0.3 (loss of 1/3 of a possession)

Points per shot = (sum of all shot results) / 36

Sample card rating: Charles Barkley

Shots per game: 12 (my assumption: 6 inside, 4 outside, 2 penetration)
Outside column: 14.5 X-chances * 2 = 29.0
6.85 O-chances * 1 = 6.85
4 F(2)-chances * 0.78 = 6.24
Total points per shot = 42.09 / 36 = 1.17
Penetrate column: 1.4 X-chances * 2 = 2.8
8.65 O-chances * 1 = 8.65
15 F(2)-chances * 0.78 = 23.4
Total points per shot = 34.85 / 36 = 0.97
Inside column: 8.05 X-chances * 2 = 16.1
3.55 O-chances * 1 = 3.55
10 F(2)-chances * 0.78 = 15.6
5 X+F(1)-chances * 2.78 = 13.9
Total points per shot = 49.15 / 36 = 1.37
Total Value of shot card: 6(1.37) + 4(1.17) + 2(0.97) = 14.84 points

Other examples: Christian Laettner 12.89; Mookie Blaylock 11.88; John Stockton 12.51

Three-point bonus

I have excluded three-pointers from the principle shooting rating, since the three-point shot is generally optional. Instead, this is incorporated as a separate bonus to reward exceptional shooters. The bonus is based upon the number of outside shots per game (see above). It is arbitrarily assumed that the most prolific shooters will take half of their attempts from beyond the arc. A successful three-pointer gives three points. Hence, the three-point bonus is:

(# of outside shot attempts / 2) * (success chances / 36) * 3 points

Examples: Barkley: - card rating is 2-3, 11 = 5 chances
(4/2) * (5/36) = 0.833; ie, Barkley will average 0.833 points per game from three-point range.

Other Examples: Laettner 0.667; Blaylock 4.0; Stockton 3.25; Reggie Miller 5.25

Fast-Break Shooting:

Calculations for fast-break shooting are based upon the (liberal) assumption of 30 fast-break attempts per game. You may want to adjust these numbers based upon your style of play. The action deck assigns shots to each position player, either directly or as the result of a pass from a teammate. I have incorporated the Dazzler results into the passing category; for purposes of the shooting rating, it is assumed that all shots are read directly from the shooters' cards. Thirty shots would be distributed as follows: RG 8, LG 8.5, RF 7.5, LF 3, C 3.

The formula is simple: Shot rating * (chances/36)

Example rating: Barkley (LF)

Chances: 5.5X= 11.0
4 XF1= 11.12
8 F2= 12.48
6 T= -6.0
Total= 28.6/36= 0.79 points per shot
Rating= 3 shots * 0.79 points per shot = 2.38 points per game on fast-break shooting

Other ratings: Laettner 1.01, Blaylock 9.18, Stockton 13.84

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