Winning ways

　　Ever since the stunning victory of Deep Blue, a program running on an IBM supercomputer, over Gary Kasparov, then world chess champion, in 1997, it has been clear that computers would dominate that particular game. Today, though, they are pressing the attack on every front. They are the undisputed champions in draughts and Othello. They are generally stronger in backgammon. They are steadily gaining ground in Scrabble, poker and bridge. And they are even doing pretty well at crossword puzzles. There is one game, however, where humans still reign supreme: Go. Yet here too their grip is beginning to loosen.

　　Go is a strategic contest. Each player tries to stake out territory and surround his opponent. The rules are simple but the play is extraordinarily complex. During a game, some stones will “die”, and some will appear to be dead but spring back to life at an inopportune moment. It is often difficult to say who is winning right until the end.

　　Deep Blue and its successors beat Mr Kasparov using the “brute force” technique.

　　Unfortunately, brute force will not work in Go. First, the game has many more possible positions than chess does. Second, the number of possible moves from a typical position in Go is about 200, compared with about a dozen in chess. Finally, evaluating a Go position is fiendishly difficult. The fastest programs can assess just 50 positions a second, compared with 500,000 in chess. Clearly, some sort of finesse is required.

　　In the past two decades researchers have explored several alternative strategies. Now, however, programmers are making impressive gains with a technique known as the Monte Carlo method. Given a position, a program using a Monte Carlo algorithm contemplates every move and plays a large number of random games to see what happens. If it wins in 80% of those games, the move is probably good. Otherwise, it keeps looking.

　　This may sound like a lot of effort but generating random games is the sort of thing computers excel at. In fact, Monte Carlo techniques are much faster than brute force. Moreover, two Hungarian computer scientists have recently added an elegant twist that allows the algorithm to focus on the most promising moves without sacrificing speed.

　　The result is a new generation of fast programs that play particularly well on small versions of the Go board. In the past few months Monte Carlo-based programs have dominated computer tournaments on nine��-and 13�瞝ine grids. MoGo, a program developed by researchers from the University of Paris, has even beaten a couple of strong human players on the smaller of these boards—unthinkable a year ago. It is ranked 2,323rd in the world and in Europe’s top 300. Although MoGo is still some way from competing on the full�瞫ize Go grid, humanity may ultimately have to accept defeat on yet another front.

　　考研詞匯：

　　stun[stʌn]

　　vt.使暈倒，使驚嚇，打暈;n.暈眩，打昏，驚倒

　　dominate[ˈdɔmineit]

　　v.①支配，統(tǒng)治，控制;②占優(yōu)勢

　　[真題例句]The coming of age of the postwar baby boom and an entry of women into the male�瞕ominated (①) job market have limited the opportunities of teenagers who are already questioning the heavy personal sacrifices involved in climbing Japan�餾 rigid social ladder to good schools and jobs.[2000年閱讀4]

　　[例句精譯] 戰(zhàn)后嬰兒出生高峰期的到來及婦女進入男性為主的就業(yè)市場，限制了青少年的發(fā)展機遇，這些青少年已經(jīng)開始質疑在進好學校、找好工作、攀登日本等級森嚴的社會階梯的過程中所做出的巨大的個人犧牲是否值得。

　reign[rein]

　　v.①(over)統(tǒng)治，支配;②盛行，占優(yōu)勢;n.①統(tǒng)治，統(tǒng)治時期，支配;②朝代

　　[真題例句](72) The existence of the giant clouds was virtually required for the Big Bang, first put forward in the 1920s, to maintain its reign (n.①) as the dominant explanation of the cosmos.[1998年翻譯]

　　[例句精譯] (72)巨大的宇宙云的存在，實際上是使20年代首創(chuàng)的大爆炸論得以處于宇宙起源論的主導地位所不可缺少的。

　　supreme[su:ˈpri:m]

　　a.①極度的，比較重要的;②至高的，比較高的

　　[真題例句]The Supreme (②) Court�餾 decisions on physician�瞐ssisted suicide carry important implications for how medicine seeks to relieve dying patients of pain and suffering.[2002年閱讀4]

　　[例句精譯] 比較高法庭關于醫(yī)生協(xié)助病人結束生命問題的裁決，對于如何用藥物減輕病危者的痛苦這個問題來說，具有重要的意義。

　　brute[bru:t]

　　a.殘忍的, 畜生般的 n. 殘忍的人, 畜生

　　sacrifice[ˈsækrifais]

　　n.①犧牲，獻身，犧牲品;②祭品，供物;v.(for，to)犧牲，獻出，獻祭

　　[真題例句]The coming of age of the postwar baby boom and an entry of women into the male�瞕ominated job market have limited the opportunities of teenagers who are already questioning the heavy personal sacrifices (n.①) involved in climbing Japan�餾 rigid social ladder to good schools and jobs.[2000年閱讀4]

　　[例句精譯] 戰(zhàn)后嬰兒出生高峰期的到來及婦女進入男性為主的就業(yè)市場，限制了青少年的發(fā)展機遇，這些青少年已經(jīng)開始質疑在進好學校、找好工作、攀登日本等級森嚴的社會階梯的過程中所做出的巨大的個人犧牲是否值得。

　　背景常識介紹：

　　人工智能(Artificial Intelligence，簡稱AI)是計算機學科的一個分支，二十世紀七十年代以來被稱為世界三大尖端技術之一(空間技術、能源技術和人工智能)，也被認為是二十一世紀(基因工程、納米科學和人工智能)三大尖端技術之一。這是因為近三十年來它獲得了迅速的發(fā)展，在很多學科領域都獲得了廣泛應用，并取得了豐碩的成果。人工智能已逐步成為一個獨立的分支，無論在理論和實踐上都已自成一個系統(tǒng)。

　　參考譯文：

　　取勝之路

　　自從1997年深藍——一個運行于IBM超級計算機上的程序戰(zhàn)勝當時的世界國際象棋冠軍加里·卡斯帕羅夫起，計算機可以統(tǒng)治這一特殊的游戲就變得不言而喻了。計算機還對每個前沿流域發(fā)起攻擊。它們是國際跳棋及黑白棋游戲無可爭辯的冠軍。在西洋雙陸棋上它們通常表現(xiàn)得更好。它們正在穩(wěn)步獲得拼字游戲、撲克和橋牌的一席之地，它們在縱橫字謎游戲中也有著優(yōu)異表現(xiàn)。然而，還有一項游戲人類仍然占據(jù)統(tǒng)治地位：圍棋。即便如此，人類在這一領域的控制力也開始喪失。

　　圍棋是一種戰(zhàn)略競爭。每位選手都要設法奪取領域并圍住其對手。在一次游戲中，一些棋子將會“死掉”，而另一些看起來死掉但卻會在不可思議的時候重獲生機。通常不到比較后是很難分出勝負來的。

　　深藍及其后繼者打敗卡斯帕羅夫所用的是暴力破解技術。

　　然而不幸的是，暴力破解在圍棋中將失去作用。首先，這一游戲有著遠多于象棋的棋位。第二，一個圍棋中的標準棋位上的走法大約有200種，而在象棋中大約是12個。比較后，評估一個圍棋棋位極度困難。比較快的程序每秒可以估測出50步棋，而在象棋中，這一數(shù)字是500000。顯然，還需要一些更好的策略。

　　過去的二十年間，研究人員探究了若干種可選性策略。然而現(xiàn)在，程序員利用一項被稱為蒙特卡羅方法的技術取得了重大進展。給定一個棋位，應用蒙特卡羅算法的程序預測每一步走法并進行大量隨機走法將會帶來什么結果。如果它在那些游戲中獲勝率是80%，那么這一步可能就是好棋。否則，它就會繼續(xù)尋找。

　　這聽起來需要花費大量努力，但是進行隨機游戲正是計算機擅長的地方。事實上，蒙特卡羅技術要比暴力破解技術快得多。此外，兩名匈牙利計算機科學家比較近又向其中增加了一種一流的手法使得該運算法則能夠在不損耗速度的前提下集中關注比較可能的棋路。這一切的結果是能夠很好地在小棋盤上進行圍棋的新一代快速程序的研發(fā)。

　　在過去幾個月中基于蒙特卡羅技術的程序已經(jīng)統(tǒng)治了9格和13格計算機圍棋大獎賽。MoGo，一個由巴黎大學研究人員開發(fā)的程序已經(jīng)在過去一年在小棋盤上出乎意外地打敗了諸多人類圍棋高手。該程序目前的世界排名是2323位，而在歐洲則處于前300位。盡管MoGo在完整棋盤上的競爭還有一段路要走，但是人類比較終將不得不接受又一個領域的失敗。