美國職棒打者生涯表現之探討

Study on Career Performance of Hitters in Major League Baseball

劉必然(Pi-Lan Liu)

《嶺東體育暨休閒學刊》 9期 (2011/06) Pp. 49-61

https://doi.org/10.29849/JPELLTU.201106.0005

摘要

職業球團與球員簽訂合約的年數與年薪，以及球員交易，都需要預測球員未來的表現。目前職業球團普遍使用的方法，就是根據該球員前幾年的表現，因此需要明確的評估方法，可以用來預測球員未來的表現。本研究之目的為根據四項修正後的數據：三壘安打率、打擊率、保送率、純長打率，探討美國職棒打者生涯表現的趨勢。研究對象為美國職棒1987-2006年共20個球季間，至少出賽8年以上，且每年都出賽達到定期出賽球員（Regular Player）標準的打者，共有223名打者。為了將不同年代的打者表現都放在同一個基準點上比較，根據Schell（2005）所使用的各個數據修正方式，將各打者各年的數據轉換成以1977-1992年國家聯盟為基準。之後再將轉換後的數據對年齡繪製趨勢圖，分析打者生涯變化趨勢。結果發現，在美國職棒以速度見長的打者，在27歲左右達到生涯的巔峰，之後便逐漸下降；打擊率方面，高打擊率的打者，通常附帶著一定的選球能力和長打率，而生涯表現也相對的穩定；選球方面，隨著年齡增長，呈現日漸上升的趨勢，因此可知，隨著經驗累積，有助於提升打者被保送的能力；長打雖會隨年齡增長而衰退，但是幅度並不大。因此，生涯純長打率在聯盟前25%的打者，即便已超過30歲，都還有一定的長打威力。透過本研究，可提供球團在簽訂球員合約，以及進行球員交易時的參考。

關鍵字

三壘安打率 ； 打擊率 ； 保送率 ； 純長打率

並列摘要

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 using 4 adjusted statistics: triple rate, batting average, base on balls, and isolated power. The subjects included Major League Baseball hitters who have played regularly at least 8 years during 1987-2006, totaling 223 hitters. In order to compare the hitters from different era, statistics from Major League Baseball was converted to the standard of National League during 1977-1992, according to Schell (2005). The converted data was used to analyze the performance change throughout the career. The results showed that, in Major League Baseball, the hitters with good speed reached their peak in about 27 years old, then showed steady decline. The hitters 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 hitters with career isolated power in top 25% of the league still maintained considerable slugging power after 30 years of age. The results of this study can be used as the reference for signing contracts and trading players.

並列關鍵字

triple rate ； batting average ； base on balls ； isolated power