※ [本文转录自 jimcal 信箱] 作者: [email protected] ([email protected]) 标题: How Many Assists Did Acie Law Really Have? 时间: Tue Oct 23 16:34:28 2007 作者: jimcal (太夸张了吧 ) 看板: WolfCave 标题: How Many Assists Did Acie Law Really Have? 时间: Tue Oct 23 15:03:46 2007 这篇文章是用 telnet 打的 希望不要有排版错误或是乱码出现... 我在订了 Baseball Prospectus 之後，想起他们新增了 Basketball Prospectus (http://www.basketballprospectus.com/ 有兴趣可以瞧瞧 :P) 浏览一下看到这篇文章，由於我有注意 Acie Law，就翻译出来分享。 原则上翻译这件事还是有侵犯着作权之虞，假装贵版是小众市场没有公开散布， 也请大家低调 XD http://www.basketballprospectus.com/article.php?articleid=14 October 17, 2007 Hometown Scoring How Many Assists Did Acie Law Really Have? by Ken Pomeroy Sometimes, the most common statistics are taken for granted as being the truth. It's assumed that the numbers we use represent an accurate historical record but occasionally they do not. Anyone who has ever tried to do a little scorekeeping on their own has surely experienced the frustration of trying to keep up with the action. Even the basics like points and rebounds are not easy to keep accurately. Official scorers in college basketball are no different, except that they have to record much more than points and rebounds. 有时候，最是平常的数据往往被当作事实般视为理所当然。但这些被视为精确历史纪录 的数据有时并不是那麽贴近事实。任何想要尝试亲自纪录球赛数据的人都能够深切体 验到那种跟不上球员动作的挫折感。即使是像分数以及篮板这种基本的数据也不是那묊麽简单可以解决。这对於在大学篮球层级的记分员来说也是一样，特别是他们记录的 不只是得分和篮板。 Though the scoring operation at a Division I game is sophisticated, there are still errors made. In large part, these are random errors. Perhaps on rare occasions a basket is assigned to the wrong player, and a little more frequently a rebound is given to someone erroneously. Just because Player A gets an extra rebound credited to him in a game, however, doesn't mean he'll see his rebound totals inflated consistently the rest of the season. This was just an unintentional error of an otherwise diligent scorekeeper. 即使在分区赛中的计分系统十分复杂，仍然有许多错误。大抵来说是一些随机的误失ꄊ。也许在一些罕见的情况里得分被记到错误的球员身上，记错篮板可能再多一些吧。 只是球员 A 在比赛中多得了一个篮板，并不因此在剩下的球季里篮板就会爆增 。这只是另一个勤奋的记分员无心的失误。 The judgment stats are a little different. Some scorekeepers subconsciously employ a different definitions for a certain stats involving judgment like assists, steals and even blocked shots. Statistically, there is more variability in how scorekeepers track assists than any other basic basketball statistic. 但对於需要仰赖记分员个人判断的数据就有些不同了。有些记分员对於像助攻、抄截 甚至是阻攻这样的纪录有着不同的定义。统计上来说，对於助攻这项数据，比起别的 篮球数据，记分员的判断可能有更多的变数。 Pages 28 and 29 of The Official NCAA 2007 Basketball Statistician's Manual http://tinyurl.com/2s4dld (warning: PDF) defines an assist for college basketball: NCAA 2007 纪录组官方手册是这样定义大学篮球的助攻： A player is credited with an assist when the player makes, in the judgment of the statistician, the principal pass contributing directly to a field goal (or an awarded score of two or three points)? Philosophy. An assist should be more than a routine pass that just happens to be followed by a field goal. It should be a conscious effort to find the open player or to help a player work free? 当球员作出一个 "原则上" 的传球，且这个传球直接地贡献了一个投篮命中 (或者是 被纪录为得分的两分或三分 ) 这个球员将获得助攻纪录乙次。 就球场上的认知，助 攻应该不只是个平常的传球，後面刚好跟着一个投篮命中。应该是 "找到有空档的球 员" 或者 "帮助球员找到空档机会" 。 The manual goes on to detail some scenarios that further clarify when an assist should be awarded. It's fairly specific, and it is comprehensive about defining an assist, although in the end there is still some room for interpretation. After reading the manual, I concluded that there's not as much room for judgment as one might have thought. In most cases, the process of awarding an assist is standard across college basketball. 手册上有更多的情境深入探讨怎样可以给助攻。相当仔细且容易理解，即便在最後仍然 留有一些解释空间。在读完手册之後，我的结论是当纪录时没有什麽时间可以去思考。 在大多数的情况，给助攻的程序在大学篮球里就是那样的。 With biased errors, unlike random errors, there are ways to sort out where the biases exist, and whom those errors benefit. In this case, we can compare how often a team is credited with an assist at home to how often they get an assist away from home. Since scorekeepers are largely the same people at each home game, we can single out which teams have scorekeepers that ration assists like they're gold and those that make even the most selfish players look like Steve Nash. 对於有意的纪录错误，就不像随机产生的错误一样。有许多方式可以找出到底哪里出了 错，而谁因为这些错误而受益。我们可以比较球队如何在主场获得助攻以及在客场获得 助攻。因为在主场记分员大抵都是相同的人，我们可以剔除给助攻时吝啬得像从自己口 袋掏钱一样以及那些把最自私的球员变得像 Steve Nash 的记分员。 The most generous scorekeepers were associated with the following five teams in 2007 底下是 2007 年最慷慨的记分员，分属於这五队。 Assist Percentage (A/FGM) Home Away Texas A&M 78.5 45.2 Sam Houston St. 82.6 55.0 Evansville 72.1 47.3 South Florida 74.9 52.1 Cal St. Fullerton 69.0 47.9 It turns out that the king of assist bias is the table at Texas A&M. At home, the Aggies recorded assists on 78.5% of their made field goals. It's a percentage that is ridiculous to the point of being unbelievable. Only one team in the country cleared an assist rate of 70% on the season and that was Northwestern at 71.6%. A&M did play some cream puffs at home, so perhaps a figure close to 80% could be attained over 19 games, which was the length of their home schedule. 台面上看到的助攻王是 Texas A&M。在家里，Aggies 78.5% 的投篮命中都是助攻产生 。太夸张了！只有 Northwestern 的 71.6% 是全国到哪都超过 70 % (应该是这个意思 吧) A&M 的确在主场安排了一些软柿子球队，因此让这个数据接近 80% 大约 19 场 ，也就是上季他们在主场的场次数。 Any hope of suspending disbelief is lost by knowing that away from Reed Arena , A&M was credited with assists on just 45.2% of their made baskets. That figure is significantly below the national average assist rate of 55.1%. It's a rate that, sustained for the entire season, would have ranked Texas A&M 323rd--14th-worst--in the country in sharing the basketball. So to summarize: At home, Texas A&M was one of the best assisting teams in college basketball history. Away from home, they were the worst major conference team in sharing the ball. 在知道离开 Reed Arena (应是 A&M 的主场) 之後的情况，任何期待这是一场误会的 希望都将落空。A&M 在客场仅仅有 45.2% 的投篮命中带有助攻。这个数字低跟全国平均 助攻数的 55.1%。这个延续了一整季的数据会让 Texas A&M 在球的流动上排在 323名， 全国倒数 14 名。结论是，在主场， Texas A&M 是大学篮球史上最会助攻的球队，在 客场，他们是全联盟最差的。 Away from home, A&M was playing in front of all sorts of different scorekeepers, so it's unlikely that there was a conspiracy among all or even most of them to not record Aggies' assists. No, the only explanation is that assist inflation was at record levels in College Station in 2007. It was a phenomenon that didn't go unnoticed in the rest of the conference. Texas took the unusual step of voiding assists that were credited to its own team in a game at Texas A&M. (Note: under NCAA rules this a step that doesn't affect the official statistics, only Texas' internal records.) 在客场， A&M 在各种不同的计分员手下比赛，因此要说这是阿共仔的阴谋或是大部分 的记分员都没有记到 Aggies' 并不太可能。唯一的解释就是这个助攻的夸大创下了在 A&M 主场的纪录。而这个现象并没有悄悄地在联盟里的其他地方发生。 Texas 用不寻 常的方式避免助攻只记到他们自己球队里。 So how many assists did the Aggies really have? Let's use their road assist percentage as a guide. The average NCAA scorekeeper gives the home team five more assists per 100 made field goals than he/she gives the opponent. This could be real, but it's probably not. You wouldn't think there would be a home-court advantage for passing, especially since we are accounting for the number of field goals made in this study. If we evenly distribute that 5% bias between the home and road team, Texas A&M's true assist percentage on the road was 45.2% +2.5%, or 47.7%. If we assume this was their true assist percentage in all games, then we can apply that figure to the 908 field goals A&M made for the season. This yields a "real" assist total of 433--158 fewer than were actually recorded. 所以到底 Aggies 到底有多少助攻呢？ 让我们用他们的客场助攻率来作为基准。平均 来说，NCAA 的记分员们每一百次出手命中当中，给主场队伍多五个助攻。这可能是真的 ，但也不见得。你不会认为在传球上会有主场优势，特别是我们计算的是投篮命中这个 数据。如果我们平均地分配这 5% 的偏差到主客队，Texas A&M 真正的助攻率在客场修 正为 47.7%。如果我们将这个数字当作他们真正的助攻数，那我们可以应用这个数据到 本季他们所命中的 908 个投篮命中当中。这产生出真正的助攻总数是 433，比原来少了 158个。 Now to the question that is the basis for this article. Applying this reduction equally to each A&M player would reduce Acie Law's assist total from 169 to 124, or from 5.0 per game, ranking 63rd in the nation, to 3.6 and out of the top 200. Law was credited with a career-high 15 assists in A&M's home win over Texas in February. We don't know how many he really had, but it's safe to say that 99% of NCAA scorekeepers would have recorded a lower number. 现在这个问题就是本篇文章的基础。把这个减少的助攻数平均地分配到 A&M 的球员， 将会使 Acie Law 的助攻总数从 169 来到 124，每场从 5 个，联盟排名第63，下降 到 3.6个，联盟排名200以外。 Law 在二月那场主场胜拿到生涯最高的 15 个助攻。 我们不知道他真正应该有多少，不过可以说 99% 的 NCAA 记分员都会记上一个更低的 数字。 Before wrapping this up, it's only natural to look at the opposite end of the spectrum. While on balance, there's a tendency for home scorekeepers to give their players an assist boost, this isn't true everywhere. The folks with the strictest definition of an assist? 在下结论之前，自然得从另一个角度看看。为了平衡，主场的记分员有可能对他们的 球员给多一些助攻，不过这不是到哪都适用的。谁会是对助攻判断最严厉的记分员呢？ Assist Percentage (A/FGM) Home Away New Mexico St. 46.3 60.1 Northern Colorado 50.9 60.6 Lafayette 57.7 67.1 Illinois 57.8 66.0 Long Island 42.3 50.4 Nobody was stingier about doling out assists than the table at the Pan American Center, where they ignored about one out of every four assists that their counterparts in other arenas were counting. This means that New Mexico State point guard Elijah Ingram was better at setting up his teammates than his stats suggest. Officially, he had 35 assists at home. Had he recorded assists at the rate he did on the road, he would have had 47 home helpers. 没有人会比 PAN American Center 更吝於发放助攻。相较於别的球场，他们平均四个 就忽略了一个。这代表 New Mexico State 的控卫 Elijah Ingram 比起他的数据更能 组织他的队友。正式的来说，他在主场有 35 个助攻。要是以他在客场的表现来看， 他可以拿到 47 个。 That might not seem like a dramatic difference, but you can really get a feel for how subjective assists are by magically trading the Aggie scorekeepers in College Station for the ones in Las Cruces. If we could do that, our best estimate of Ingram's home assist total would have it increasing to 78, or more than doubling. His assist rate for the season would have risen from 17.3% to 26.4%, or from a below-average playmaker to a respectable one, ranking him just outside the top 150 nationally. Similarly, Law's assist rate would have decreased from 30.8% to 19.7%, making him look like a score-first point guard--which is closer to the truth. 这或许不是相当大的差距，但是你可以感受到助攻是如何地被 Aggie 的记分员给主观 地转换。如果我们可以这样做，我们预测 Ingram 的主场助攻数可以达到 78 个，甚至 是两倍。他的助攻率可以从 17.3% 提升到 26.4%，或者说从低於平均的指挥官成为令人 尊敬的指挥官，使他成为全国 150 名的控卫。同样地， Law 的助攻率会从 30.8% 下降 到 19.7 %，使他变成一个得分第一的控卫，而这是比较贴近真实的。 For the most part, scorekeepers across the nation have a similar view of an assist. As long as D-I nation spans more than 300 teams, however, there will be outliers. In this case, it may have influenced the view of Acie Law's and Elijah Ingram's talents. More than likely, Ingram was better at setting up his teammates, even though the stats indicate that Law was easily the better assist man. There is no statistic in major sports as subjective as the basketball assist, and we should consider that before reading too much into a player's or team's assist rate. 最主要的，全国各地的记分员对於助攻都有相似的观点，只要像这样全国有三百队的 分区，总是会有一些 outliers (这个我统计课学到就是这样叫，中文是？)。在这个 例子当中，或许会影响到对 Acie Law 以及 Elijah Ingram 的天赋判断。即使数据 上 Law 很容易被认为是个能够助攻的人，但是 Ingram 却可能在这件事上比他做得 更好。在主要的运动上没有一个数据像篮球的助攻这麽地主观，而在深入了解一个 球员或球队的助攻率之前，我们都应该仔细的想一想。 -- My blog: Yankees, Sixers, Jimcal http://blog.xuite.net/jimcal/blog 关於洋基、七六人的部落格 -- 修改了一些翻译上的问题，也谢谢板众的回应。的确，有时就连数据本身都不见得可以 反映出球员真正的实力，有太多球员并非在数据上表现亮眼却是球队不可或缺的力量。 会翻译这篇文章的原因只是在篮球界终於也有像 Baseball Prospectus 这样讨论数据 的网站 (我之前都只有看 82games)，刚巧这篇文章的主角是贵板受瞩目的新人。想说 拿来这边比较能引起回响吧？我也不觉得此文一出 Acie 就会被看衰，攻击型的後卫 说不定後市还比较看好哩！(我自己 FB 也是有选他阿 XD) ※ 编辑: jimcal 来自: 220.140.209.212 (11/02 23:11)