Portugal's performance in this tournament has shown clear fluctuations. In the group stage, they secured two victories thanks to solid defense and counter-attacking efficiency, but in the final round against a weaker opponent, they exposed a lack of midfield control, with the attack overly reliant on wing breakthroughs and set pieces. In recent friendlies, Portugal has shown a high error rate when facing high-pressing teams, and the fitness reserves of key players have been tested by a congested schedule. Spain, on the other hand, has continued their traditional possession-based system, remaining unbeaten in three group matches with an average possession rate of over 65%, though their conversion rate remains a persistent issue. Against counter-attacking teams recently, they have often fallen into the predicament of "dominating without scoring," but their defense has demonstrated strong coordination in covering and positioning, with the goalkeeper's consistent performances being a key safeguard. Historical head-to-head records show that Portugal and Spain have traded wins in official matches, with Spain holding a slight edge in their last 10 encounters (4 wins, 3 draws, 3 losses). Notably, both of their knockout-stage meetings went to extra time or penalties, with Spain emerging victorious in the classic clashes of the 2010 World Cup and 2012 European Championship. However, Portugal defeated Spain away in the 2020 Nations League, breaking a decade-long winless streak. Psychologically, Portugal's adaptation to Spain's possession system is improving, while Spain must remain wary of Portugal's "de-centralized" tactical evolution following Cristiano Ronaldo's departure. Key players: For Portugal, Bernardo Silva and Leão are the most threatening attacking outlets—Silva's runs into the half-spaces and Leão's dribbling ability on the flanks will directly challenge Spain's defensive structure. However, midfield linchpin Neves is a doubt due to muscle fatigue, and his absence would put greater pressure on Portugal's ball progression from midfield. For Spain, the midfield duo of Pedri and Rodri is crucial for controlling the tempo, while winger Nico Williams is in red-hot form, with his cutting inside and shooting potentially serving as a breakthrough weapon. On the injury front, Spain's starting left-back Gayá has been ruled out, raising doubts about the defensive stability of his replacement, which could become a key target for Portugal's attacks. Tactically, Portugal is likely to deploy a 4-3-3 formation, relying on compact defensive lines and quick counter-attacks to create threats, with both wingers dropping back to wide midfield positions in a 5-4-1 defensive block. Spain will adhere to their 4-3-3 possession system, using high pressing in midfield to force Portugal into passing errors, but their lack of an efficient target man against deep-lying defenses could be exploited. The key battle will be whether Portugal can exploit the space left by Spain's high defensive line when Spain holds over 70% possession, while Spain faces the risk of increased defensive exposure if they fail to score within 60 minutes due to fatigue. The AI comprehensive prediction model gives Portugal a 21.6% win probability, a 35.0% draw probability, and Spain a 43.4% win probability, while mainstream odds imply a Spanish win probability of approximately 51.5%, a draw probability of 27.3%, and a Portuguese win probability of 21.0%. Comparing the two, the AI's draw probability (35.0%) is significantly higher than the bookmakers' implied probability (27.3%), while the AI's Spanish win probability (43.4%) is notably lower than the market expectation (51.5%). This discrepancy suggests the market may be overestimating Spain's dominance while underestimating Portugal's resilience in knockout stages. Given the frequency of draws in historical meetings and the fact that both sides have weaknesses in attack and defense, there is a "value opportunity" here: the draw option has the most prominent AI win probability advantage and deserves close attention.