This is Scientific American's 60-second Science, I'm Steve Mirsky.
With a full month of the regular season to play, the 2019 New York Yankees had set a Major League Baseball record for injuries. That medical crisis led to what the online sports publication The Athletic reported on January 3rd as "sweeping changes" to their training and strength-and-conditioning programs. When I read that news, I thought, of course, of traffic cameras, which sometimes, and reasonably, get placed at sites that have a disproportionate number of accidents in a given year.
"The fact that there's a higher rate of accidents will be partly due to chance because it will fluctuate over the course of time. Sometimes it will be less; sometimes it will be high."
David J. Hand, on the Scientific American Science Talk podcast in 2014. He's emeritus professor of mathematics and senior research investigator at Imperial College London, where he formerly held the chair in statistics. He was on the podcast to talk about then new book The Improbability Principle: Why Coincidences, Miracles, and Rare Events Happen Every Day.
So what does the Yankees' revamped training staff potentially have in common with traffic cameras?
"Now if we look back at last year and identify the places which have particularly high rates of accidents, the high rate of those places will be due to a sum of two things: the natural degree of dangerousness of those places, plus the fact that that particular year just happens to be a bad year—there were more accidents than normal at that year. But because it is a high rate of accidents, we're now going to put a camera there."
Again, a particular year just happens to be a bad year.
"Now what happens next year? The natural dangerousness of the place hasn't changed; it's still the same corner or intersection or whatever. But the chance bit of the number of accidents there, well, it could be low just as easy as high next year. On average, it will be lower than the high rate we saw. So next year, the rate will come down. It won't be because of the camera, it will just be because of natural fluctuation, removing that sort of chance part. But it will look as if putting the cameras there has improved things."
Hand continued: "The fact is, however, the speed cameras do work. There is no question that they do reduce the rate of accidents but not as much as a superficial analysis failing to take into account the Law of Selection and Regression to the Mean makes it look like."
As a big Yankees fans, I hope they have no injuries at all in 2020—and that the new training staff is outstanding. But when the team's injury rate falls—as it's almost certain to do after a record-setting bad year—I'll keep in mind that at least part of the drop may be due not to Tinkers, nor to Evers, but to chance.
For Scientific American's 60-second Science. I'm Steve Mirsky.
常规赛赛程还有一个月，而2019年纽约洋基队已经创下了职业棒球大联盟的伤病纪录 。这场医疗危机导致在线体育刊物《The Athletic》在1月3日进行了报道，称洋基队的训练和力量与调节项目发生了“彻底改变” 。我看到这则新闻时，自然想到了交通摄像头，它有时被合理地安装在一年中事故数量不成比例的地点 。
“事故发生率较高的部分原因是偶然性，因为事故会随着时间的推移而波动 。有时会少一些，有时会很高 。”
这是大卫·汉德2014年做客《科学美国人》节目的“科学对话”播客时所说 。他是伦敦帝国理工学院的名誉数学教授和高级研究调查员，此前他曾担任该学院统计学专业负责人 。他在播客上谈到了当时出版的新书《不可能原理：为何巧合、奇迹和罕见事件每天都会发生》 。
“如果我们回顾一下去年，找出事故发生率特别高的地点，会发现事故发生率高的原因有两个：这些地方的自然危险程度，以及那一年恰巧是个糟糕的年份，该年发生的事故比平常年份要多 。但由于事故率很高，我们现在要在那里安装摄像头 。”
“那明年会怎样？地点的自然危险程度并未改变，仍然是同样的拐角或十字路口等地方 。但是明年那里发生事故的几率可能会很低，也可能会很高 。平均而言，几率会低于我们看到的高发生率 。所以，下一年的发生率会下降 。但这不是因为摄像头，而是因为自然波动，排除了那种偶然部分 。不过，看起来安装摄像头能起到改善作用 。”
汉德接着表示，“事实上，测速摄像头确实起到了作用 。毫无疑问，这些摄像头确实降低了事故发生率，但降低程度并没有表面分析显示的那样多，那些分析没有考虑到选择法和趋均数回归 。”
作为洋基队的球迷，我希望他们在2020年不会受伤，新的训练人员也很出色 。但洋基队的伤病率下降时——在创纪录的糟糕一年后这是肯定会发生的事情——我会记住，至少有一部分下降可能不是因为Tinkers，也不是因为Evers，而是由于偶然性（Chance）（三者分别为20世纪初期小熊队的游击手,二垒手,和一垒手） 。
谢谢大家收听科学美国人——60秒科学 。我是史蒂夫·米尔斯基 。
1. have in common 共有的；相同的；
We should put aside our differences and discuss the things we have in common.
2. happen to do sth. 碰巧；凑巧；
She ha ppened to be out when we called.
3. on average 平均起来；按平均值；
American shares rose, on average, by 38%.
4. no question 毫无疑问地；毫无异议地；
There's no question she is the best comedienne in this country.