Bottom Line Up Front (BLUF):
This 2023 study, authored by LT Sawyer J. Rogers and LT William C. Weldin at the Naval Postgraduate School, analyzes over 232,000 training data points from the Basic Underwater Demolition/SEAL (BUD/S) program to identify human characteristics that correlate with successful training evolution outcomes. Key findings indicate that older, married, and officer candidates—especially those who are taller, lighter, and right-handed—exhibit higher pass rates. Conversely, lower pass rates are associated with minority candidates, particularly Black individuals in water-based evolutions. The research advocates for greater automation and digitization of Naval Special Warfare (NSW) training data systems to enable predictive modeling, reduce clerical inefficiencies, and better inform selection processes.
Demographic and Physical Characteristics (Averages)
| Trait | Mean | Std. Dev. | Min | Max |
|---|---|---|---|---|
| Age | 26.89 years | 3.81 | 17 | 41 |
| Height | 70.32 inches | 2.58 | 60 | 84 |
| Weight | 179.01 lbs | 18.45 | 117 | 260 |
Gender Distribution
| Gender | Proportion |
|---|---|
| Male | 99.98% |
| Female | 0.002% (2 total) – excluded from most analysis |
Marital Status
| Status | Proportion |
|---|---|
| Single | 89.09% |
| Married | 10.62% |
| Divorced/Unknown | 0.28% |
Race/Ethnicity
| Race | Proportion |
|---|---|
| White | 84.51% |
| Hispanic | 7.35% |
| Other Race | 4.92% |
| Asian | 1.24% |
| Black | 1.06% |
| Indian | 0.49% |
| Pacific Islander | 0.42% |
Enlistment Status
| Status | Proportion |
|---|---|
| Enlisted | 86.24% |
| Officer | 13.76% (inferred from 100% – enlisted %) |
Hand Dominance
| Dominance | Proportion |
|---|---|
| Right-Handed | 57.70% |
| Left/Unknown | 42.30% |
Key Findings
1. Predictors of Higher Pass Rates:
- Age: Older candidates had significantly higher pass rates across nearly all training events. For example, candidates aged 33 had a 3.6% higher overall pass rate than those aged 21.
- Height: Each additional inch of height increased the pass rate by ~0.295%.
- Weight: Additional bodyweight slightly decreased pass probability (−0.027% per pound), suggesting leanness may be advantageous.
- Marital Status: Married individuals had ~1.2% higher pass rates than single individuals.
- Officer vs. Enlisted: Enlisted SEAL candidates had a 5.4% lower pass rate than officers.
- Right-Handedness: Right-handed candidates passed at a slightly higher rate (~0.8%).
2. Predictors of Lower Pass Rates:
- Race/Ethnicity:
- Black candidates had a 5.25% lower overall pass rate than White candidates, with an especially sharp drop in water-based events: 7.3% lower in swim events and 16.7% lower in other water evolutions.
- Asian and Indian candidates also had statistically lower pass rates.
- Hispanic and Pacific Islander categories did not show statistically significant differences in overall performance.
- Divorced/Unknown Marital Status: Associated with a ~2.9% lower pass rate compared to single individuals.
3. Evolution-Specific Outcomes:
- The predictive power of variables like age and weight varied across evolution types:
- Obstacle courses saw the largest positive association with age and height, with older and taller individuals tending to perform better on the obstacle course compared to other fitness tests.
- Swim and underwater tests had the largest drop-offs for minority candidates, particularly Black trainees.
Author’s Discussion & Future Research Opportunities
The authors highlighted several critical takeaways and avenues for future research:
1. Maturity Predicts Success
- Older and married individuals, and officers, outperformed younger, single, and enlisted candidates.
- This trend suggests that maturity and experience play a role in success at BUD/S. However, the authors caution against selecting only older candidates, noting the potential loss of younger candidates who could develop into strong performers later.
2. Racial Disparities
- The most concerning finding was the lower pass rates among Black candidates, particularly in water evolutions.
- The authors recommend further investigation into:
- Access to water-based preparatory training before entry.
- Potential cultural or socioeconomic barriers that could be addressed with pre-BUD/S support programs.
3. Right-Handedness
- The consistent, albeit modest, advantage of right-handed candidates raised questions. The cause is unknown and warrants further investigation to determine whether course design or instruction style plays a role.
5. Expanded Research Scope
- The authors propose extending this type of research to:
- Special forces units in other U.S. military branches.
- Allied special operations communities.
- Additional variables such as geographic background, BMI, family structure, and athletic history.
Conclusion
This study represents a significant leap in applying data science to military training analysis. It offers a statistically robust view of which personal characteristics are most predictive of success in one of the most elite training pipelines in the world. However, the findings also raise important concerns—especially related to racial disparities and data quality—that deserve further attention.
The authors recommend that Naval Special Warfare modernize its data infrastructure, embrace predictive analytics, and use insights like these to:
- Optimize candidate selection and development.
- Better allocate training resources.
- Create more equitable outcomes without compromising standards.
Bibliography
Rogers, S. J., & Weldin, W. C. (2023). Impact of Human Characteristics in Basic Underwater Demolition/SEAL (BUD/S) Training Performance. Naval Postgraduate School. [NPS-PM-23-224].
https://apps.dtic.mil/sti/pdfs/ADA279547.pdf