Can Poisson Modeling Predict China U23’s Chances Against Vietnam?

Data Overview

China U23: 4 matches (1 win, 3 draws), 1 goal scored, 0 goals conceded.

Vietnam U23: 4 matches (4 wins), 8 goals scored, 3 goals conceded.

Poisson Modeling Approach

Goals are modeled as independent rare events following a Poisson distribution.

Baseline goal rate : 52 goals in 24 group matches → 2.17 goals per match (≈1.08 per team).

Attack/defence strengths : strength = team average goals ÷ baseline. China attack = 0.23, defence = 0.30 (after Bayesian shrinkage). Vietnam attack = 1.62, defence = 0.69.

Opponent‑strength adjustment : Using FIFA rankings, opponent factor = 66 / average opponent ranking. China factor = 1.14, Vietnam factor = 0.89.

Expected goals (λ) : λ = attack × opponent factor. λ₁ (China) ≈ 0.35, λ₂ (Vietnam) ≈ 0.65.

Poisson probability formula

P(k;λ)=e^{-λ} λ^{k} / k!

Applying the formula to λ₁ and λ₂ yields the joint score probability matrix (excerpt):

China win in regular time: 17.1 %

Draw (extra time/penalties): 45.6 %

Vietnam win in regular time: 37.2 %

Penalty‑shootout adjustment

Historical shoot‑out win rates: China 55 %, Vietnam 45 %.

Overall advancement probabilities:

China: 17.1 % + 45.6 % × 55 % = 42.2 %

Vietnam: 37.2 % + 45.6 % × 45 % = 57.8 %

Sensitivity Analysis

China attack strength (λ₁)

λ₁ = 0.15 → 34.8 %

λ₁ = 0.25 → 38.6 %

λ₁ = 0.35 → 42.2 % (baseline)

λ₁ = 0.45 → 45.7 %

λ₁ = 0.55 → 48.9 %

λ₁ = 0.65 → 52.0 %

Vietnam attack strength (λ₂)

λ₂ = 0.40 → 50.9 %

λ₂ = 0.50 → 47.2 %

λ₂ = 0.65 → 42.2 % (baseline)

λ₂ = 0.80 → 37.7 %

λ₂ = 1.00 → 32.5 %

λ₂ = 1.20 → 27.9 %

Penalty‑shootout win rate

40 % → 35.4 %

45 % → 37.7 %

50 % → 40.0 %

55 % → 42.2 % (baseline)

60 % → 44.5 %

65 % → 46.8 %

Key Findings

Advancement probability exceeds 50 % only when China attack λ₁ > 0.4 and Vietnam attack λ₂ < 0.6 (the “green” region).

If Vietnam λ₂ > 1.0, China’s chance drops below 35 % regardless of its attack (the “red” region).

Current model predicts a 42 % chance for China and a 58 % chance for Vietnam to reach the final.

Model Limitations

Unmodelled factors include fatigue from extra minutes, psychological pressure, tactical nuances, and the exceptional performance of goalkeeper Li Hao.

Final prediction: China U23 ≈ 42 % chance to advance; Vietnam U23 ≈ 58 % chance.