MEXICO CITY, June 24 : Czech Republic coach Miroslav Koubek blamed "stupid mistakes" and exhaustion from heavy travel for his team's World Cup exit after a 3-0 defeat by co-hosts Mexico on Wednesday left them bottom of Group A. Koubek said Czech football urgently needed to raise its technical standards to compete internationally following their return to the World Cup after a 20-year absence. • Koubek defended dropping striker Patrik Schick, saying Adam Hlozek was preferred for his physical