(又來獻醜了，這篇翻的滿心虛的，一樣歡迎指正)
(趴兔比較有探討內容，這篇比較像是熱身)
原文出處：
The Hardball Times
http://ppt.cc/QfnB
A Primer on Tommy John Surgery: Part One
JUNE 30, 2014 BY JEFF ZIMMERMAN
淺談Tommy John手術: 趴萬
Tommy John surgery (TJS) interest was all the rage earlier this season, when
everyone’s favorite pitcher, Jose Fernandez, found out that he needed the
surgery. Besides Fernandez, 51 other pitchers have needed to go under the
knife for the same procedure this year alone. Since Fernandez was lost for
the season, quite a bit of additional research has become available to help
fill in some of the blanks.
從這球季開始團報TJ似乎蔚為一股風潮，大家喜愛的投手如Jose Fernandez被診斷出需要
進行手術，除此之外還有51位投手需要在今年動刀。既然JoFz已經球季報銷了，我們需要
一些額外的研究來填補這樣的空白。
Today and tomorrow, what I have attempted to do is compile as much of the
current knowledge about Tommy John surgeries in the major leagues as I could,
with the hope that bringing it together can help us build our knowledge base.
In doing so, I have identified a number of areas for further research, and I
will interject these in italicized paragraphs labeled “Help Out” during the
course of these two articles, as well.
Once TJS became the rage this spring, it seemed like it was a requirement to
write about the subject. Examples include ESPN, Grantland, Sports
Illustrated, Yahoo!, Newsday,Bleacher Report, FiveThirtyEight, The New York
Times, Drive Line Baseball andNPR.
We’ll cover much of the same ground in these two articles as, again, my goal
is to compile as much information as possible, and these articles had some
very valuable information within them. I will also be adding my own and other
information as well. I have put in all the known information I have found
useful on major league Tommy John surgeries. As additional information
becomes available, I plan to go back and update these articles with the
missed or new data. Basically, I envision these articles to be one-stop
shopping for years to come on known facts for the surgery at the major league
level.
(按：這三段主要描述作者分析的想法，略去不翻，不過可參考原文中其他關於TJS的討論
文章，包括 ESPN, Grantland, Sports Illustrated, Yahoo!, Newsday,Bleacher
Report, FiveThirtyEight, The New York Times, Drive Line Baseball andNPR)
Before looking at the state of research on TJS, we need to start with The
List. Baseball research was in its infancy until Retrosheet was freely
available to everyone. Looking at Tommy John surgeries was impossible until
people knew who had had the operation. A list had to be created. Back in
2011, I asked the community’s help in creating a list and got enough players
to at least get a starting point.
Then came Jon Roegele. He combined my list with one of his own and also
gathered input from others to create a list of 448 players who had undergone
Tommy John surgery. As of today, the list stands at 737 players, and Jon adds
players as soon as he finds out about them. A big thanks needs to be given to
Mr. Roegele, as just about none of the following work could have been done
without his efforts.
在瞭解TJS目前研究的現況前，我們需要名單。棒球研究直到Retrosheet(按：詳細紀錄大
聯盟逐場比賽相關數據的網站)的出現才變的比較成熟；同樣的在大家知道誰動過手術前
，研究TJS也是不可能的。為了建立這個名單，在2011年就已經透過幫助取得動過TJS的投
手名單。Jon Roegele將我的名單和他的結合，再加上其他來源，總共收集了448個球員。
陸續蒐集直到今天，已經有737位球員了。
The research and debate on the subject has increased as the number of MLB
pitchers who have needed the operation has exploded over the past couple of
seasons. This graph illustrates the changes on a year-by-year basis:
With the list complete, some useful information can be obtained. Today, I
will focus on how a player’s production is affected by the surgery, as well
as how long it takes to return from the surgery.
As an aside, allow me to apologize in advance if I have missed anybody’s
research. Quite a bit has become available recently, and it is a challenge to
keep up with it all. Please let me know in the comments and I will add the
information to the article.
隨著過去幾個球季大聯盟投手動手術的人數爆炸性的增加，相關研究與討論也越來越多，
下圖秀出逐年進行TJS的人數：
(圖)http://i.imgur.com/5f0K8ck.jpg
當名單完成之後，我們就可從中獲得些有用的資訊；此篇文章我將會著重在球員的表現如
何受到手術的影響，以及手術後需要多久時間回到球場。
Effects of Tommy John Surgery on Performance
Tommy John手術對球員表現的影響
When looking at how pitchers performed before and after the surgery, I am
going to go with information I know and trust because I worked on it. In the
The Hardball Times Annual 2013, Brian Cartwright and I looked at the effects
of returning from Tommy John surgery.
Starting with velocity, we looked at four seasons.
‧ Season 1: Last full healthy season
‧ Season 2: Season of TJS
‧ Season 3: Season of return from TJS
‧ Season 4: First full season after TJS
當要觀察球員在手術前後表現差異時，我採用去年與Brian Cartwright所做的統計。
從球速開始，總共統計四個球季
球季1：上一個完整健康的球季
球季2：動TJ手術的球季
球季3：動完TJ手術後回來的球季
球季4：TJ手術後第一個完整球季
With this set-up, a healthy baseline is set before and after the operation.
Also of note, not all pitchers are compared in each group. If a pitcher had
Tommy John surgery in spring training, there would be no data to compare for
the “Season of TJS.” Additionally, we used both weighted (by total pitches)
and unweighted samples because pitch speed stabilizes quickly.
藉由這樣的設定，我們會有一個健康的基準線分別在手術前與後。值得注意的是，並不是
所有的投手都可以在每個群體被比較，如果投手是在春訓去動TJS，當然就沒有數據可以
與「動TJ手術的球季」做比較。除此之外，我們同時運用加權(總投球數)與未加權的數據
，因為球速其實是很快就穩定的數據。(按：參考http://ppt.cc/9BKH，大概3場比賽之後
，所丟速球球速就與整季平均誤差在1mph內了。)
‧ Season: Weighted, Non-weighted
‧ Season 1 to 2: -0.10, -0.37
‧ Season 1 to 3: +0.14, +0.05
‧ Season 1 to 4: -0.07, -0.80
Besides our article, The American Journal of Sports Medicine looked at
velocity decline and found similar values.
‧ Time Frame: Decline
‧ 1 year before surgery to 1 year after: -0.2 mph
‧ 1 year before surgery to 2 years after: -0.1 mph
‧ Up to 3 years before surgery to up to 3 years after: -0.4 mph
球速統計結果如下：
球季比較 加權 未加權
1-2 -0.10 -0.37
1-3 +0.14 +0.05
1-4 -0.07 -0.80
除此之外，期刊The American Journal of Sports Medicine(AJSM)也做過球速下降的研
究，並得到相近的結果
時間區段 下降幅度
手術前1年與手術後1年 -0.2mph
手術前1年與手術後2年 -0.1mph
手術3年以前與手術3年以後 -0.4mph
With the preceding information, a couple of points can be made.
1. Tommy John surgery doesn’t help a pitcher increase velocity. While there
was a small increase from Season 1 to Season 3 in our sample, it would not be
worth it for a pitcher to miss at a minimum one season to see a 0.1 mph bump
that they then will immediately lose. Probably most of the increase is from a
decline in production before the injury knocked them out of action, as well
as the time spent rehabbing.
2. While TJS doesn’t increase velocity, it does seem to limit the effects of
aging. On average, a pitcher with lose 0.25 mph on his fastball per season.
With the time off for the surgery, some need rest and a regimented workout
plan, as Tommy John recipients come back not aging as much. Here is an aging
curve graph for all pitchers and those who had the surgery.
依據這些資訊，可以提出幾個觀點：
1. TJS並無法幫助投手增加球速。雖然從球季1至球季3球速有一點上升，這並不值得一個
投手犧牲最少一個球季去換取0.1mph的增加，且很快就會下降回來。這個增加可能是因
為在傷勢實際爆發之前，就已經影響了表現，手術後只是恢復而已。
2. 雖然TJS無法增加球速，不過似乎可以抑制老化的影響。平均來說，投手每季速球球速
都會下降0.25mph。當因為動手術而關機期間，是需要休息與大量的復健，因此從手術
復原回來後自然老化不會那麼劇烈。下圖比較了所有投手的老化曲線，並與動過手術的
做比較。
(圖) http://i.imgur.com/SpRgojf.jpg
After surgery, pitchers don’t see a huge jump in velocity. So how did they
perform coming back? I will use the same two studies to tackle this question.
In the Hardball Times study, we looked at the “percentage difference between
their pre-surgery projected performance and their actual performance.”
既然手術之後，投手球速並不會有顯著增加，那對於他們復出後的表現是如何呢？我同樣
利用這兩份研究去處理這個問題。在硬球時報的研究裡，我們檢視「手術前預期的表現與
實際表現的差異百分比」。
TJ手術後的統計數據與手術前預期表現比較