This is a guest post by Adam Bernfeld. He is trained as an engineer and likes to apply his analytical nature to baseball to differentiate 「what seems」 vs. 「what is」. His interests include PITCHf/x, DIPS, the concept of clutch, and Laura Posada. 这篇是来自Adam Bernfeld的文章。他是一名工程师，并且喜欢利用自己的专长来区分「 似乎是」与「肯定是」。他关注於PITCHf/x，DIPS，concept of clutch与Laura Posada(Posada的老婆)。 「Statistics are like women: mirrors of purest virtue and truth, or like whores to use as one pleases.」 -Theodor Billroth 「统计数据有时可以反映出真实性，有时却可依照个人观点来使用。」- Theodor Billroth It is true that in a vacuum, statistics are almost entirely useless. One can manipulate the numbers to prove any side of an argument. They can however provide illumination in instances where what seems may differ from what is. For example, a few years ago before John Dewan wrote the Fielding Bible, a lot of Yankee fans truly did believe that Derek Jeter was a good defensive shortstop because he both seemed like a good fielder, and our broadcasters told us that he was a good fielder. Similarly, watching a Yankee game, one could be led to believe that Chien-Ming Wang possesses the best sinker in all of baseball. After all, it is 94 miles-per-hour and looks like it is dropping off a cliff. Surely no one's could be better, right? Well, using PITCHf/x data, I hope to crown the true 「Sultan of Sink.」 事 实上在个案中，统计数据几乎是完全没有用的。任何人都可以巧妙的运用数字，甚至 举例子来解释似是而非的论点。例如，几年前在John Dewan的着作Fielding Bible完成之 前，许多洋基迷确信Derek Jeter是一名防守优异的游击手，因为他看起来似乎是个好的 守备员，播报员也告诉我们他是一个好的防守者。同样地，观赏洋基队的比赛时，任何人 都可能认 为王建民是大联盟中最棒的伸卡球投手。毕竟他的伸卡球有94英哩的速度，而 且看起来就像从悬崖掉下来似的。肯定没有人能投的更棒，对吧?好吧，运用 PITCHf/x的 资料，我希望能找出真正的「伸卡球之王」。 For those new to PITCHf/x, it is a system developed by Sportsvision in use by Major League Baseball that uses two cameras to measure the position of the baseball between the pitcher's hand and home plate, which can be used to determine various parameters about each pitch including velocity and break (for a more thorough introduction to PITCHf/x, refer here and here). 对於PITCHf/x不熟悉的人，它是一套由Sportsvision所发展的系统，并且被大联盟所采用 ，这套系统使用了两部摄影机测量球从投手出手到本垒版之间的位置，可以测定出每一球 的速度与变化量等等数值(详细介绍请参考这里和这里)。 Using PITHf/x data compiled by Josh Kalk of The Hardball Times, detailed pitch information can be seen for individual players or in a searchable database. For this study, I will compare the speed, horizontal break and vertical break of the average signature pitch of baseball's prominent sinkerballers from the 2007 season. Based on reputation and ground ball rates, I have chosen a test group that includes: Chien-Ming Wang, Fausto Carmona, Aaron Cook, Roy Halladay, Tim Hudson, Derek Lowe, Sergio Mitre, Brandon Webb and Jake Westbrook. 利用Hardball Times网站的Josh Kalk所蒐集的PITHf/x资料，详细的投球资料可以从个别 球员或检索数据库中 查看。在本次的研究中，我将比较2007年球季大联盟中主要的伸卡 球投手的球速，水平变化与垂直变化的平均值。基於名气与滚地球比例，我挑选了包含王 建 民，Fausto Carmona，Aaron Cook，Roy Halladay，Tim Hudson，Derek Lowe， Sergio Mitre，Brandon Webb与Jake Westbrook。 http://gary711.tw.googlepages.com/20080515_table1.png Note in the chart above that the values for break represent the number of inches that the pitch moves compared to a pitch thrown without spin, or, compared to a straight pitch under only the influence of gravity. The negative numbers for horizontal break indicate that the pitch moves inside to right-handed hitters. The positive values for vertical break indicate that the pitch crosses the plate higher than a pitch without spin would have. This may seem counterintuitive as we are talking about sinkers, but in reality sinkers are thrown with backspin and do rise (resist dropping actually), albeit much less than a 4-seam fastball, so they do in fact appear to sink. A 4-seam fastball is gripped across the seams resulting in more backspin than a sinker (or 2-seam fastball) which is gripped along the seams; the more backspin, the larger the positive vertical break. For comparison, Joba Chamberlain's fastball has a vertical break of 11.42 inches, compared to the average vertical break of 4.66 for our sinkerballer group. 注 意到上图中的变化量(break)是指与没有旋转的球或是只受重力影响的直球比较之下的 移动量。水平变化中的负数代表球往右打者移动。垂直变化的正数则代 表伸卡球经过本 垒版时的高度比没有旋转的球来的高。这似乎和我们所谈论的伸卡球相反，但是事实上伸 卡球是反转的而且会上飘(实际上是抵抗落下)，尽管跟四 缝线速球相比少得多，所以看 起来会下沉。由於四缝线快速球的握法跨过缝线，所以与沿着缝线握球的伸卡球(或是二 缝线速球)相比会造成较多的反转;反转越 多，正向的垂直变化越大。相较之下，Joba Chamberlain的快速球有11.42寸的垂直变化，而我们的伸卡球投手群平均变化量则是4.66 寸。 The chart above can be shown graphically by plotting horizontal break on the x-axis and vertical break on the y-axis with pitch speed represented by dot size. In this graph, the lower right hand corner, the point (0,0), represents a pitch thrown without spin. 上图以图形化显示，X轴代表横向变化，Y轴代表垂直变化，圆点的大小则代表球速。在这 张图中，越接近右下角(0,0)这点，表示球的旋转越少。 http://gary711.tw.googlepages.com/20080515_chart1.png In hopes to build some sort of consensus as to who possesses the best sinker, I used the three PITCHf/x values (speed, horizontal break, vertical break) to create a z-score (also called a 「standard score」) which is a statistical quantity used to combine multiple values measured on different scales. I then ordered the average z-score of each pitcher from high to low to rank the pitcher with the best combination of speed and break. Think of this as an index of the 「stuff」 on the pitcher's sinker, or a 「sinker-stuff index」. This value appears on the chart below alongside each pitcher's groundball to flyball ratio (GB/FB), swing and miss (S&M) percentage, fair ball (FB) hit percentage, and fair ball extra base hit (XBH) percentage. All of these values are for sinkers only, except GB/FB which is the rate for all pitches thrown regardless of type. 为了找出谁是最佳的伸卡球投手，我使用了三个PITCHf/x数值(速度，水平变化，垂直变 化)以建立Z值(又 称为「标准值」)，这个统计值结合由数个标准测量出来的数据。我将 结合了每位投手的球速与变化量的平均Z值由高到低排列出来。我们可以将之视为「球威 」的 指标。这个值与投手的滚飞比(GB/FB)，挥空(S&M)率，球被有效击中(FB)的比率， 与球被有效击中形成长打(XBH)的比率一同列在下 图中。除了滚飞比(GB/FB)以外，所有 的这些数据都是只统计伸卡球。 http://gary711.tw.googlepages.com/20080515_table2.png The results of this study are interesting. While throwing one of the harder sinkers in the league (second only to Fausto Carmona), Chien-Ming Wang's sinker actually sinks less than any other member of the test group. This is certainly a surprising observation. In fact, his sinker also has the lowest horizontal break, causing his sinker to rank 8th out of 9 in my sinker-stuff index. This certainly manifests itself in his below average groundball to flyball ratio and sinker swing and miss percentage. Remarkably however, compared to the test group Wang has the lowest percentage of hits off of sinkers, and by far the lowest percentage of extra base hits off of sinkers. 这 个研究的结果很有趣。虽然王建民能投出大联盟中速度最快的伸卡球之一(仅次於 Fausto Carmona)，但是事实上他的伸卡球和其他的研究对象相比下沉幅度的比较小。这 无疑是一个令人感到意外的发现。王建民的伸卡球水平变化量最小，也使得 他的伸卡球 球威在九个人中排名第八。这也显示在低於平均的滚飞比与伸卡球挥空率。然而与研究对 象的其他投手相比，很显然的，王建民的伸卡球拥有最低的被有 效击中率与被长打率。 While some may chalk these low hit percentages up to luck, it appears that something deeper may be happening here. Finally though, the stats are pointing towards something that we already believed to be true. What seems agrees with what is, and that is the fact that Chien-Ming Wang rarely allows a hard hit ball off of his sinker. Why then, is his sinker so successful in spite of the fact that it moves so much less than those of his peers? Maybe my methods are all wrong (I hope not). Maybe pitch speed is more significant than pitch break (possibly). Maybe the ease of his delivery, which also includes a pronounced, varied hesitation, has a great effect on hitters' timing (possible). Maybe Wang's defense is better at turning batted balls into outs than the others on this list (unlikely). Maybe the DIPS people are right and hit percentages are no more than statistical variations (possibly, although I believe that DIPS applies more loosely to sinkerballers). Maybe it is a combination of all of these factors or even something that I have not thought of (likely), so please feel free to throw out explanations of your own. 当有些人将 这些较低的有效击中率归因於好运时，也许还有些东西需要讨论。最後虽然 统计资料指出某些我们相信的事是确实的。事实上王建民很少备有打有效击中他的伸卡 球，尽管变化幅度不如其他人，为什麽他伸卡球仍然投的如此成功?也许我的评估方法全 部都错了(我希望不是)。也许球速比变化幅度更为重要(有可能)。也许 他从容不迫的投 球影响了打者的挥棒时机(有可能)。也许在防守方面，王建民在将被击出的球转换成出局 数上比其他人厉害(不大可能)。也许强调DIPS的人 是对的，而被打击率只是统计变数而 已(有可能，虽然我相信DIPS运用在身卡球投手身上比较不严谨)。也许是所有因素的组合 ，或是还有我没有考虑到的地方 (不大可能)，所以请随意的提出你的见解。 Regardless of the reasons, I am glad that Wang is a Yankee as he gives us a very good chance to win once every five days. While his low ranking in my sinker index does not correlate with his outstanding results, at the end of the day I'll always take the results over the 「stuff」. Though after much machination, I have not definitively proved where Wang's sinker ranks amongst his brethren, but I hope that this was interesting and informative, and maybe allows you to view the game and the sinker in a different light the next time the Wanger takes the hill. 不 管这些推论如何，我很高兴王建民是洋基球员，并且有很大的机会每五天能赢一场球 。虽然他在我的伸卡球指标中排名较低，但是这和他出色的表现一点关系也没 有，最後 我会以成绩取代「球威」。尽管经过了一连串的比较，最後我仍然没有证明王建民的伸卡 球在众伸卡球投手中的排名，但是我希望这次的研究是有趣与有益 的，也许能让你在王 建民下次上场时从不同的角度观赏比赛。 http://riveraveblues.com/2008/05/12/wang-the-sultan-of-sink-2769/ -- Gary says... http://www.gary711.net http://gary711.idv.st --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 221.169.150.114 ※ 编辑: supergary 来自: 118.171.165.214 (05/16 11:11) ※ micotosai:转录至看板 Baseball 06/03 20:08