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Defensive Innovation

CARUSO

Named after Alex Caruso — the guard whose defensive profile exemplifies what this metric is built to find. No backronym: the name precedes the acronym.
Composite Metric Defensive Model 2016–17 through 2025–26 Interpretability-First
Three-stage model
  • Stage 1 — Observable components: rim protection (shot suppression + deterrence), STOP rate (steals, charges, recovered blocks), rebounding over expected, and defensive activity (deflections, de-duplicated from steals). All measured per possession and normalized by position.
  • Stage 2 — Learn component weights: a gradient-boosted model trained on player seasons from 2016–17 through 2023–24. Target variable is multi-year defensive RAPM. Produces a stat-based defensive prior.
  • Stage 3 — RAPM blend: low-minute players lean on the prior; high-minute players lean on observed single-season impact. Position-specific shrinkage — bigs stabilize faster than guards.

The stated goal is interpretability first. Unlike APEX's Defensive Impact pillar (which blends D-LEBRON, D-EPM, and DBPM directly), CARUSO makes each component visible — you can see not just the score but the four inputs driving it.

"Defense is one of the hardest things to talk about clearly in basketball analytics. We have plenty of strong all-in-one metrics that do a good job describing overall impact. The issue is not really accuracy. It's explanation. When a player grades out well or poorly, it's often unclear why. CARUSO started as an attempt to answer a simpler question: Can we build a defensive metric where the reasons are obvious?"

Posted by ConfusedComet23 on r/nba  ·  Full methodology on Substack (Hard Screen Herald)

Percentiles shown are relative to the full league. RIM = rim protection, REB = rebounding over expected, STOP = possession-ending events, DEFL = deflections.

Rank Player Team · Pos CARUSO RIM REB STOP DEFL
1 Alex Caruso OKC · G 2.19 39 71 99.9 93.9
2 Ajay Mitchell OKC · G 1.89 56 83 92 27
3 Neemias Queta BOS · Big 1.84 99 98 82 38
4 Cason Wallace OKC · G 1.84 53 43 96 78
5 Jaylin Williams OKC · F 1.78 80 98 66 55
6 Ronald Holland II DET · F 1.64 77 77 98 4
7 Paul Reed DET · F 1.59 75 84 100 93
8 Rudy Gobert MIN · Big 1.51 98 93 65 58
9 Chet Holmgren OKC · Tweener 1.43 99.9 92 89 56
10 Isaiah Hartenstein OKC · Tweener 1.36 99 97 78 81
Rank Player Team · Season CARUSO
1 Rudy Gobert UTA · 2020–21 2.55
2 Rudy Gobert UTA · 2016–17 2.49
3 Joel Embiid PHI · 2017–18 2.43
3 Alex Caruso CHI · 2022–23 2.43
5 Giannis Antetokounmpo MIL · 2019–20 2.36
6 Alex Caruso OKC · 2024–25 2.27
6 Paul George OKC · 2018–19 2.27
13 Draymond Green GSW · 2016–17 2.09

ConfusedComet23 is explicit that CARUSO is a work in progress. Rim protection and STOP rate are the most reliable components — clean, stable signals with consistent relationships to multi-year RAPM. Rebounding is the weakest link: the best way to capture rebounding impact is RAPM-style regression, and box plus tracking data historically predict RAPM rebounding impact poorly.

The OKC Problem

Six of the top 10 in the 2025–26 leaderboard play for Oklahoma City, which also leads the league in defensive rating by a wide margin. Critics correctly note that team context contaminates individual grades, and that CARUSO may overweight possession-ending events — OKC's specific defensive strength — relative to other forms of elite defense.

Stat Card
Type Composite metric
Category Defensive Innovation
Era 2016–17 to present
Trained on Multi-year def. RAPM
All-time peak 2.55 (Gobert, 2020–21)
Namesake Alex Caruso
Created by ConfusedComet23
Source Box + tracking data
How APEX measures defense →