前期子多是甜蜜的陷阱
黑白棋最反直覺的一課：開局和中盤翻越多子，往往局勢越差。因為你的每一顆子都是對手翻回來的原料，而盤面上子越多，你的可選落點通常越少。強者在前中盤刻意「少吃」，把棋子數壓低，讓對手先陷入無處可走的境地。記住這個原則再去看棋盤，很多看似虧的下法會突然合理起來。
角是唯一翻不回去的格子
四個角沒有任何方向可以被夾住，一旦佔角，這顆子永遠是你的，而且以角為端點的整條邊都可能變成穩定子。黑白棋的中盤戰略幾乎可以濃縮成一句話：逼對手把角送給你，同時絕不主動送角。
C 位與 X 位：送角的兩種方式
緊貼角的三個格子是危險區。與角同邊相鄰的兩格俗稱 C 位，斜向相鄰的一格是 X 位。過早落子在這些位置，等於給對手一個把你夾向角的支點——其中 X 位最危險，因為它只在對角線上，幾乎必然把角拱手讓人。這些格子不是永遠不能下，而是要等到該角的歸屬已定、或你能算清後果時才碰。
行動力：看不見的比分
真正的中盤比分不是棋子數，而是行動力——雙方各有幾個合法落點。每一手都問自己：這步棋是增加了我的選擇，還是減少了對手的選擇？把對手的行動力壓到極低，他就只剩下壞棋可下，C 位、X 位遲早被迫送出。本站的規則會在一方無合法落點時自動跳過該回合——被迫跳過通常就是行動力崩潰的訊號。
殘局換一套算法
最後十幾手，遊戲性質改變：空格有限、翻轉可以精算，這時候才輪到「數子」上場。留意奇偶：每個獨立空區的格子數是奇是偶，決定誰能下到該區的最後一手——最後一手往往能翻回一大片。殘局階段寧可多花時間逐格計算，也不要憑感覺快下。
在本站怎麼玩
棋子數量面板即時顯示雙方子數，看著它練習「前期少吃」會很直觀。三檔難度中，困難檔的電腦按位置價值評估落點而不只是貪吃子，正好可以驗證上面的策略。勝場與對局數保存在目前瀏覽器。
實戰檢驗：開一局黑白棋，整場只盯行動力，不看子數。
Early material is a sweet trap
The most counter-intuitive lesson in reversi: flipping many discs early usually makes your position worse. Every disc you own is raw material for the opponent to flip back, and crowded colors tend to have fewer legal moves. Strong players deliberately keep their disc count low through the midgame — sometimes called the evaporation strategy — steering the opponent into running out of decent moves first. Hold that thought and many "losing" moves start to look right.
Corners are the only permanent squares
A corner disc cannot be flanked from any direction. Once taken it is yours forever, and the edges radiating from it can become chains of stable discs. Midgame strategy compresses into one sentence: force your opponent to hand you a corner, and never volunteer one yourself.
C-squares and the X-square: two ways to donate a corner
The three squares touching each corner are the danger zone. The two on the adjacent edges are the C-squares; the diagonal neighbor is the X-square. Playing them early gives the opponent a pivot to flank you toward the corner — the X-square is the worst offender, sitting on the corner's diagonal and all but gift-wrapping it. These squares are not forbidden forever; they simply wait until the corner's fate is settled or you can calculate the consequences exactly.
Mobility is the hidden score
The real midgame score is mobility — how many legal moves each side holds. Ask of every move: does it expand my options or shrink theirs? Squeeze the opponent's mobility hard enough and only bad squares remain for them; the C- and X-squares get forced out of their hands. On this site, a side with no legal move is skipped automatically — being skipped is usually the sound of mobility collapsing.
The endgame runs on different math
In the last dozen moves the game changes character: few empties remain and every flip can be counted exactly, so disc-counting finally matters. Watch parity — whether each isolated empty region holds an odd or even number of squares decides who plays last into it, and the last move often flips a wall of discs. Slow down and count; endgame intuition is precisely what loses won games.
On this site
The live disc-count panel makes the "stay small early" discipline easy to practice — watch it stay low on purpose. On hard difficulty the computer evaluates positional value rather than raw disc count, which makes it the right opponent for everything above. Wins and games persist in the current browser.
Put it to the test: play Reversi watching only mobility, never the disc count.