Summary: | 碩士 === 國立臺灣體育學院 === 運動管理學系碩士班 === 96 === The prediction of performance for professional baseball players is required in determining the length and price of contracts and trades. The Method which teams generally use at present, is according to this player's performance in previous years. Therefore, a more reliable method is required to estimate the future performance of the players. The purpose of this research is to analyze the trend of career performance in Major League Baseball and Chinese Professional Baseball League using 4 adjusted statistics: triple rate, batting average, base on balls, and isolated power. The subjects included Major League Baseball players who have played regularly at least 8 years during 1987-2006, totaling 223 players. The players who have had 1000 or more career at bats during 1990-2007 in Chinese Professional Baseball League were also involved, totaling 147 players. In order to compare the players from different era, statistics from Major League Baseball was converted to the standard of National League during 1977-1992, according to Schell (2005). The statistics in Chinese Professional Baseball League was compared to the league average of the year. The converted data was used to analyze the performance change throughout the career. The results showed that, in Major League Baseball, the players with good speed reached their peak in about 27 years old, then showed steady decline. The players with high batting average usually combined with good baseball on ball ratio and slugging average. The performance of these players was relatively stable throughout the career. The ability to get base on balls increased with age, indicating that the experience can help. Slugging average showed small magnitude of decline with age. The players with career isolated power in top 25% of the league still maintained considerable slugging power after 30 years of age. The results were similar in Chinese Professional Baseball League, but the peak performance in the career was reached in the earlier age then that in Major League Baseball. The results of this study can be used as the reference for signing contracts and trading players.
For is it given to same datum point is it compare to pay to display player of various years, and probe into different ability separately, this research is adopted by Schell (2005) All data used revise the way, calculate player's data through 5 steps, drawing the trend picture to the age after changing, find out player's career development trend, for using to assess player's ability.
Found finally, an excellent player good at the speed of MLB about 27 years old to reach the peak of the career, later dropped gradually. The player of the high batting average, usually lead attaching certain on base ability and power, and career performance relative stability too. The base on balls ability increase with the age, the trend of rising day by day appears. Although player's power will decline with the age, the range is not big, so, player's career pure power rate at the top 25% in the league , even if already over 30 years old, have certain hold their power. The CPBL have similar phenomenon too. The only different is the peak of player's career performance is earlier than MLB. It may due to the difference of professional baseball system in different countries.
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