NSBA Draft Analyticsembargoed · 2026-06-06

scibowl_coverage_baseline.md

Science Bowl Coverage Baseline (SSB-2026)

Science Bowl Coverage Baseline (SSB-2026)

Natural-roster (school-formed team) baseline for subject coverage, breadth, and celerity, built from real Science Bowl buzz-level data. Feeds:

Source & method

Data quality: excellent. Every team's reconstructed buzz points exactly equal its actual recorded game points (mean |diff| = 0.0 across all 84 teams; 100% reconcile). The one caveat we had to fix: raw player_id/team_id are per-game identifiers, not stable entities (one person → many player_ids). We aggregate on (name, team, tournament) and (team, tournament) to recover true season totals. After aggregation: 84 stable teams, 366 stable players. All teams played ≥4 games (median 5; the deep-bracket teams reach 9–12). One more nuance: bonuses are team-answered (their buzz rows have a blank player_id), so the player table is a pure tossup profile and bonus points live only in the team table — exactly as Science Bowl scores them. All team-level findings below are unaffected.

A. How common is solid coverage of each subject?

Across all 84 natural teams (covered = ≥2 correct tossups in the subject; punted = 0):

Subject Covered (≥2 TU) Punted (0 TU) Mean pts share
Chemistry 97.6% 1.2% 16.9%
Earth/Space 96.4% 2.4% 16.7%
Physics 94.0% 3.6% 18.7%
Math 92.9% 1.2% 17.8%
Energy 92.9% 2.4% 13.5%
Biology 90.5% 0.0% 16.4%

Takeaway: in natural rosters, every subject is covered by the large majority of teams — there is no "commonly punted" subject. Biology is essentially never fully punted (0% with zero correct TU). Energy carries the smallest point share (~13.5%), reflecting that it is a smaller slice of the question distribution, not that teams neglect it. Coverage of all six is the norm, not the exception — the natural baseline is broad. Where teams differ is in depth/celerity, not breadth.

B. Breadth vs concentration — which wins?

Win-pct quartile n_subjects_covered breadth_HHI (lower=broader) avg_celerity tu_conv%
Q1 (worst) 5.14 0.261 0.048 0.451
Q2 5.75 0.225 0.071 0.550
Q3 5.90 0.195 0.116 0.633
Q4 (best) 6.00 0.180 0.155 0.707

Takeaway: breadth beats concentration. Balanced, generalist teams win more. A specialist stack (high HHI) is negatively associated with success even after adjusting for raw point output. In the natural game, you cannot win by punting a subject and over-loading another — the question distribution is even, so coverage gaps are directly exploited.

C. Celerity (buzz speed) vs success and coverage

Takeaway: celerity is a first-class success signal. Elite natural teams win by buzzing earlier across a broad base, not by out-grinding on a narrow specialty.

D. What the TOP teams actually look like

Top-10 teams by win-pct vs the rest:

Group mean n_subjects_covered mean breadth_HHI mean celerity
Top 10 6.00 0.179 0.172
Rest 5.59 0.224 0.084

Every single top-10 team covers all 6 subjects, runs a near-balanced profile (HHI ≈ 0.18, vs the 0.167 floor of a perfectly even team), and buzzes ~2× faster than the field. Representative top-8 subject-share profiles (% of positive points):

Montgomery Blair A  W%1.00 cel.148  bio18 che19 phy15 mat20 ess16 ene12   (textbook balance)
Mission San Jose A  W%0.92 cel.233  bio18 che17 phy17 mat16 ess18 ene14   (most balanced + fastest)
MIT Team #2         W%0.91 cel.162  bio23 che25 phy10 mat23 ess10 ene 9   (the rare tilt: bio/chem/math heavy)
Davidson A          W%0.90 cel.154  bio 8 che16 phy21 mat19 ess18 ene17   (light bio, deep everywhere else)

Even the "tilted" top teams still cover every subject (≥2 TU) — they just weight toward strengths. The dominant pattern is balance + speed.

Implications for NSBA (A16 / A18)

  1. Optimal coverage = all subjects covered, balanced. The natural baseline says broad beats narrow. A drafted roster that punts a subject to stack another is fighting the evidence: HHI concentration correlates with losing.
  2. Celerity is a draftable edge. Buzz speed is nearly as predictive of winning as conversion and points. NSBA should treat a player's speed profile, not just accuracy, as a core asset.
  3. Natural rosters set a high coverage bar (≈90–98% per subject). For A18, the right comparison is: do NSBA drafted rosters achieve the same near-universal six-subject coverage that school teams reach organically? If drafting produces more coverage gaps than natural formation, that is a draft-process inefficiency worth flagging. (Note: CS scarcity is NSBA-internal and not in this baseline.)

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