Case Study 1: The 2016 Warriors - Win Shares in a Historic Season

Introduction

The 2015-16 Golden State Warriors won 73 games, breaking the 1995-96 Chicago Bulls' record of 72 wins. This case study examines how Win Shares distributed credit across the roster and what this reveals about the metric's ability to capture both individual excellence and team chemistry.

Season Overview

Historic Achievement

The Warriors finished 73-9, posting: - Offensive Rating: 114.5 (1st in NBA) - Defensive Rating: 103.8 (5th in NBA) - Net Rating: +10.7 (1st by significant margin) - Point Differential: +10.8 per game

Key Players

Win Shares Distribution

Total Win Shares by Player

Key Observations

1. Curry's Historic OWS

Stephen Curry's 15.1 OWS ranked as one of the highest single-season totals ever recorded: - Curry 2015-16: 15.1 OWS - Jordan 1987-88: 14.2 OWS - LeBron 2008-09: 14.5 OWS

This reflected his historic scoring efficiency: - 30.1 PPG on 50.4% FG, 45.4% 3PT - True Shooting: 66.9% (historically elite) - Usage Rate: 32.6%

2. Draymond's Defensive Dominance

Green's 5.7 DWS led the team and ranked among league leaders despite: - Playing significant minutes at undersized center - Limited individual defensive statistics (1.5 BPG, 1.5 SPG)

This demonstrates how DWS credits team defensive success, with Green's minutes on an elite defense earning high DWS even without traditional "defensive" box score numbers.

3. Win Shares Sum to Team Wins

Total team Win Shares (~72) closely matched actual wins (73), validating the metric's design. The slight discrepancy reflects estimation variance in the methodology.

Analytical Deep Dive: Curry's Value

Marginal Offense Calculation

Curry's OWS derives from his marginal offensive contribution:

Points Produced: ~2,100 (scoring + assists) Possessions Used: ~1,800 Points per Possession: 1.17

Marginal Calculation: - Replacement level: ~0.92 points/possession - Marginal rate: 1.17 - 0.92 = 0.25 points/possession above replacement - Marginal points: 0.25 × 1,800 = 450 marginal points

Converting to OWS: - Team marginal points per win ≈ 30 - Curry OWS ≈ 450 / 30 = 15.0 (approximate)

Why Curry's WS/48 Is Historic

Curry's 0.318 WS/48 ranks among the highest ever: - Reflects exceptional efficiency at high volume - 66.9% TS% with 32.6% usage = unprecedented - Created value both scoring and facilitating

Only a few players have approached this level: - Michael Jordan 1987-88: 0.291 - LeBron James 2012-13: 0.322 - David Robinson 1993-94: 0.315

Team Construction Analysis

Credit Distribution

The Warriors' Win Shares distribution reveals their construction philosophy:

High Concentration at Top: - Curry: 25% of team Win Shares - Top 3 (Curry, Klay, Draymond): 54% of team Win Shares

Deep Contribution: - 10 players with positive Win Shares - Bench contributed ~16 total Win Shares - Role players all with positive WS/48

Synergy Effects

Win Shares may understate or misattribute value due to synergies:

Curry-Draymond Pick-and-Roll: - Curry's gravity created open shots for others - Draymond's passing from short roll created layups - Win Shares credits Curry for his points, Draymond for his assists - But the system created more value than individuals alone

Death Lineup: - With Green at center, team posted +28.7 net rating - Individual Win Shares don't fully capture lineup-specific effects - System value partially attributed to individuals

Limitations Revealed

What Win Shares Captured Well

1. Curry's offensive dominance: His historic efficiency shows clearly in OWS
2. Team defensive balance: DWS correctly identified Green as defensive anchor
3. Depth contribution: Bench players received appropriate credit
4. Total allocation: Team Win Shares matched actual wins

What Win Shares Missed

1. System effects: The Warriors' motion offense created opportunities beyond individual stats
2. Gravity: Curry's off-ball threat isn't fully captured by OWS
3. Defensive scheme: Green's defensive quarterbacking exceeded box score impact
4. Chemistry: The team was greater than sum of Win Shares

Postseason Context

Playoff Win Shares

The Warriors lost the Finals 4-3 to Cleveland despite leading 3-1. Win Shares from the regular season didn't predict playoff outcomes, highlighting: - Small sample variability - Opponent adjustments - Injury/fatigue effects

Lessons Learned

For Win Shares Interpretation

1. Win Shares validate individual excellence: Curry's historic season shows clearly
2. Team context matters: Good teams have higher total Win Shares to distribute
3. Defense is approximated: DWS captures team defense more than individual
4. Rate vs. counting: WS/48 better compares players; WS measures total contribution

For Team Building

1. Concentration of star talent: Curry's 18 WS shows superstar value
2. Complementary pieces: Klay and Draymond provided 21 combined WS
3. Depth matters: Bench Win Shares contributed to sustainability
4. System design: Win Shares can't fully capture system effects

Conclusion

The 2015-16 Warriors provide a fascinating case study in Win Shares interpretation. The metric correctly identified Curry's historic offensive season and appropriately distributed credit across a deep roster. However, the metric's limitations—particularly in capturing system effects, defensive scheme value, and playoff performance—remind us that Win Shares is one tool among many for player evaluation.

Discussion Questions

1. How might Win Shares be modified to better capture system-based offense like the Warriors'?

2. Does Curry's 17.9 Win Shares adequately reflect his value to the 73-win team?

3. Why might playoff Win Shares differ significantly from regular season projections?

4. How should teams use Win Shares in constructing championship rosters?

Data Exercise

Using Basketball-Reference data:

1. Calculate the percentage of team Win Shares attributed to the top 3 players for each of the top 5 teams by wins in 2015-16.
2. Compare regular season Win Shares to playoff Win Shares for the Warriors' core four (Curry, Thompson, Green, Iguodala).
3. Identify which role players outperformed their regular season WS/48 in the playoffs.