(又来献丑了，这篇翻的满心虚的，一样欢迎指正)
(趴兔比较有探讨内容，这篇比较像是热身)
原文出处：
The Hardball Times
http://ppt.cc/QfnB
A Primer on Tommy John Surgery: Part One
JUNE 30, 2014 BY JEFF ZIMMERMAN
浅谈Tommy John手术: 趴万
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.
从这球季开始团报TJ似乎蔚为一股风潮，大家喜爱的投手如Jose Fernandez被诊断出需要
进行手术，除此之外还有51位投手需要在今年动刀。既然JoFz已经球季报销了，我们需要
一些额外的研究来填补这样的空白。
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：这三段主要描述作者分析的想法，略去不翻，不过可参考原文中其他关于TJS的讨论
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.
在了解TJS目前研究的现况前，我们需要名单。棒球研究直到Retrosheet(按：详细纪录大
联盟逐场比赛相关数据的网站)的出现才变的比较成熟；同样的在大家知道谁动过手术前
，研究TJS也是不可能的。为了建立这个名单，在2011年就已经透过帮助取得动过TJS的投
手名单。Jon Roegele将我的名单和他的结合，再加上其他来源，总共收集了448个球员。
陆续蒐集直到今天，已经有737位球员了。
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.
随着过去几个球季大联盟投手动手术的人数爆炸性的增加，相关研究与讨论也越来越多，
下图秀出逐年进行TJS的人数：
(图)http://i.imgur.com/5f0K8ck.jpg
当名单完成之后，我们就可从中获得些有用的资讯；此篇文章我将会着重在球员的表现如
何受到手术的影响，以及手术后需要多久时间回到球场。
Effects of Tommy John Surgery on Performance
Tommy John手术对球员表现的影响
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
当要观察球员在手术前后表现差异时，我采用去年与Brian Cartwright所做的统计。
从球速开始，总共统计四个球季
球季1：上一个完整健康的球季
球季2：动TJ手术的球季
球季3：动完TJ手术后回来的球季
球季4：TJ手术后第一个完整球季
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.
借由这样的设定，我们会有一个健康的基准线分别在手术前与后。值得注意的是，并不是
所有的投手都可以在每个群体被比较，如果投手是在春训去动TJS，当然就没有数据可以
与“动TJ手术的球季”做比较。除此之外，我们同时运用加权(总投球数)与未加权的数据
，因为球速其实是很快就稳定的数据。(按：参考http://ppt.cc/9BKH，大概3场比赛之后
，所丢速球球速就与整季平均误差在1mph内了。)
‧ 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
球速统计结果如下：
球季比较 加权 未加权
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)也做过球速下降的研
究，并得到相近的结果
时间区段 下降幅度
手术前1年与手术后1年 -0.2mph
手术前1年与手术后2年 -0.1mph
手术3年以前与手术3年以后 -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.
依据这些资讯，可以提出几个观点：
1. TJS并无法帮助投手增加球速。虽然从球季1至球季3球速有一点上升，这并不值得一个
投手牺牲最少一个球季去换取0.1mph的增加，且很快就会下降回来。这个增加可能是因
为在伤势实际爆发之前，就已经影响了表现，手术后只是恢复而已。
2. 虽然TJS无法增加球速，不过似乎可以抑制老化的影响。平均来说，投手每季速球球速
都会下降0.25mph。当因为动手术而关机期间，是需要休息与大量的复健，因此从手术
复原回来后自然老化不会那么剧烈。下图比较了所有投手的老化曲线，并与动过手术的
做比较。
(图) 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.”
既然手术之后，投手球速并不会有显著增加，那对于他们复出后的表现是如何呢？我同样
利用这两份研究去处理这个问题。在硬球时报的研究里，我们检视“手术前预期的表现与
实际表现的差异百分比”。
TJ手术后的统计数据与手术前预期表现比较