Yeah, isn't adjusted efficiency margin essentially scoring margin adjusted for competition, game location, and tempo?
KenPom appears to use the actual final score to calculate adjusted efficiency margin. Torvik uses "both the actual score and GameScript-derived score". As has been discussed, the GameScript-derived score is based on the average margin over the course of the game.
Torvik's FAQ provide more detail, but he doesn't mention how he weighs the actual score and the GameScript-derived score. As far as I can tell, he appears to give ~50% weight to each.
To see how this plays out, consider the ND and BC games.
Duke beat ND by a final score of 86-78 in 65 possessions. Duke's average margin over the course of the game was 11.1, so Torvik's GameScript-derived score was 93.1-70.9.
The table below shows the Adjusted Margins based on a) the actual final score, b) the GameScript-derived score, c) an average of the actual and GameScript-derived scores, and d) the value Torvik reports on his site.
Duke/ND | Actual
score | GameScript-
derived
score | Average
(actual &
GameScript) | T-Rank
Site |
AdjOE | 130.4 | 141.1 | 135.7 | 135.6 |
AdjDE | 111.8 | 101.6 | 106.7 | 108.5 |
AdjEM | 18.5 | 39.5 | 29.0 | 27.1 |
GameScore | 85 | 98 | 94 | 93 |
For the BC game, the actual score was 88-63. Torvik's GameScript-derived score was 81.2-69.8.
Duke/BC | Actual
score | GameScript-
derived
score | Average
(actual &
GameScript | T-Rank
site |
AdjOE | 130.9 | 120.1 | 125.1 | 124.5 |
AdjDE | 93.2 | 102.6 | 97.6 | 99.9 |
AdjEM | 37.7 | 17.5 | 27.4 | 25.8 |
GameScore | 98 | 86 | 94 | 93 |
For these two games, the adjusted efficiency margins are almost exactly flipped when using the actual score (ND = 18.5, BC = 37.7) and GameScript-derived score (ND = 39.5, BC = 17.5).
The numbers in the "Average" column appear to be closest to what Torvik lists on his site*.
KenPom doesn't report game-by-game adjusted efficiencies, but I think the "actual score" column is closest to what he does. These differences would explain why Duke's KenPom rating dropped after the ND game, but rose after the BC game, while Torvik treated both games similarly.
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*I suspect that a major difference between the values in the "average" column and the actual values from Torvik's site is that Torvik stops counting when the lead is considered 100% safe. I didn't attempt to do this. For the ND game this shouldn't make much difference as the lead wasn't considered 100% safe until 14 seconds left. On the other hand, Duke achieved a safe lead in the BC game when they went up 25 with 6:02 remaining after Cooper hit his post-technical 3 pointer. Duke played BC even over the remainder of the game, but Torvik's system should be more impressed with a 25 point win in 34 minutes (55-60 possessions) than a 25 point win in 40 minutes (67 possessions).
Either way, something seems a bit "off" about my calculations. The AdjOE's are pretty spot on, but my AdjDE's are about 2 points lower than what Torvik reports for both games.