Teams in Japan's two professional baseball leagues began to add foreign players in the early 1950s, with the average number per team reaching 5.79 in 2004. This was primarily because foreign hitters outperformed Japanese hitters. Hazard analysis shows that a poorly performing team was more likely to hire its first Caucasian and African American players earlier than a successful team. Econometric analysis of team use of foreign players over 45 seasons (1960–2004) shows that losing Central League teams used foreign players more often in following season(s), whereas past success of Pacific League teams did not affect their use of foreign players.