美國職棒大聯盟（MLB）的季後賽制度是為選拔最強球隊爭奪世界大賽冠軍。隨著時間的推移，規則結構經歷多次改變，尤其是近年來外卡制度的引入，進一步豐富賽季結束後的競爭性。季後賽通常由兩個聯盟（美國聯盟和國家聯盟）各自進行，然後由兩個聯盟的冠軍進行世界大賽（World Series）。目前的季後賽結構包含以下幾個階段：

1.外卡系列賽（Wild Card Series）：每個聯盟有六支球隊進入季後賽，分別是三個分區冠軍與三支外卡球隊。外卡球隊是各分區以外成績最好的隊伍。季後賽第一輪由三支外卡隊伍和表現最差的分區冠軍進行三戰兩勝制的比賽，勝者晉級下一輪。  

2.分區系列賽（Division Series）：進入這輪的球隊將進行五戰三勝制比賽，對戰形式根據成績排列，分區冠軍享有對陣外卡隊伍的優勢。

3.聯盟冠軍賽（League Championship Series）：七戰四勝制的比賽，勝出的球隊將成為聯盟冠軍，並進入世界大賽。

4.世界大賽（World Series）：兩個聯盟的冠軍隊伍進行七戰四勝制比賽，勝者奪得世界大賽冠軍。

外卡制度於1994年首次被引入，目的是增加季後賽的競爭激烈程度，讓更多非分區冠軍的球隊也有機會爭奪總冠軍。最初，每個聯盟只有一支外卡球隊，後來在2012年，外卡隊伍增加至兩支，並進行一場單淘汰賽決定誰能晉級下一輪。這一變動有效增加季末的緊張感和戲劇性。到2022年，外卡制度再次擴充，每個聯盟增加至三支外卡球隊，並將外卡賽改為三戰兩勝制，讓實力接近的球隊有更多機會競爭晉級資格。

優點:

1.增加競爭性：外卡制度讓更多球隊有機會進入季後賽，提升賽季末的競爭激烈程度。即使是未能獲得分區冠軍的球隊，仍有機會爭奪世界大賽的入場券，避免只有分區冠軍才有資格的單調性。  

2.延長季後賽戲劇性：外卡賽增加季後賽的不確定性。即使是表現突出的球隊，也可能在單場淘汰賽中面臨早早被淘汰的風險，這增加比賽的緊張感，吸引更多觀眾。

3.保持賽季末的興趣：由於外卡制度的存在，更多球隊在常規賽後期仍保持競爭力，這對球迷和球隊管理層都具有重要意義，讓賽季不會因某些球隊提早鎖定季後賽名額而失去看點。

缺點:

1.削弱分區冠軍的重要性：隨著外卡隊伍的增加，分區冠軍的價值被稀釋，因為非分區冠軍球隊也能輕鬆進入季後賽，甚至有可能奪冠。這讓一些認為分區冠軍應更有價值的人感到不滿。

2.增加比賽疲勞：更多的比賽意味著球員需要打更多的賽事，尤其是那些參加外卡賽的球隊。這可能會影響球隊在後續輪次中的體能與表現，特別是當外卡賽是單淘汰或短期系列賽時。

3.運氣因素增多：單場淘汰賽或三戰兩勝制容易讓比賽結果受到短期表現或運氣的影響，可能導致強隊被意外淘汰，而非靠實力走到最後。這一點讓部分球迷認為外卡制度降低比賽的公平性。

總體而言，外卡制度自引入以來有效提升MLB季後賽的吸引力與競爭性，但同時也引發對賽制公平性的討論。不過，隨著大聯盟對制度的調整與優化，這種季後賽結構逐漸成為一種經典，受到大部分球迷的認可。

The Major League Baseball (MLB) postseason system is designed to select the strongest team to compete for the World Series championship. Over time, the rules and structure have undergone multiple changes, especially with the recent introduction of the Wild Card system, which has further enhanced the competitiveness of the postseason.

MLB’s postseason typically consists of two leagues—the American League and the National League—each conducting its own playoff series, culminating in the World Series, where the champions of both leagues face off. The current playoff structure consists of the following stages:

Wild Card Series: Each league has six teams qualifying for the postseason: three division champions and three Wild Card teams. The Wild Card teams are the best-performing teams that did not win their divisions. The first round of the playoffs features a best-of-three series between the three Wild Card teams and the division champion with the worst record. The winners advance to the next round.

Division Series: The teams that advance to this round play a best-of-five series. Matchups are based on regular-season performance, with division champions having the advantage of facing Wild Card teams.

League Championship Series: A best-of-seven series determines the league champion, with the winning team advancing to the World Series.

World Series: The champions of the American League and National League compete in a best-of-seven series to determine the World Series champion.

The Wild Card system was first introduced in 1994 to increase the competitiveness of the postseason, allowing more non-division-winning teams to have a chance at the championship. Initially, each league had only one Wild Card team. In 2012, the number of Wild Card teams increased to two, with a single-elimination game determining which team advanced to the next round. This change added excitement and tension to the end of the regular season. By 2022, the Wild Card system expanded again, with each league adding a third Wild Card team and changing the Wild Card series to a best-of-three format, giving similarly ranked teams more opportunities to compete for advancement.

Advantages:

Increased Competitiveness: The Wild Card system allows more teams to enter the postseason, enhancing the intensity of competition as the regular season concludes. Even teams that did not win their divisions have the chance to compete for a spot in the World Series, preventing the postseason from being limited to division winners only.

Extended Drama in the Playoffs: The Wild Card games add an element of unpredictability to the postseason. Even strong teams may face the risk of early elimination in single-elimination games, increasing the tension and attracting more viewers.

Maintained Interest Toward the Season’s End: Thanks to the Wild Card system, more teams remain competitive in the late stages of the regular season. This is important for both fans and team management, ensuring that the season does not lose its appeal when certain teams secure playoff spots early.

Disadvantages:

Diluted Value of Division Championships: As the number of Wild Card teams increases, the significance of winning a division is reduced. Some believe that division winners should be more highly valued, as non-division-winning teams can still enter the postseason and potentially win the championship.

Increased Player Fatigue: More postseason games mean that players need to play additional matches, especially those competing in the Wild Card round. This could affect teams' physical condition and performance in later rounds, particularly if the Wild Card round involves single-elimination or short series formats.

Increased Role of Luck: Single-elimination games or best-of-three series may cause results to be heavily influenced by short-term performance or luck, potentially leading to stronger teams being unexpectedly eliminated. This has led some fans to believe that the Wild Card system decreases the fairness of the competition.

Overall, the Wild Card system has effectively boosted the appeal and competitiveness of MLB’s postseason since its introduction, though it has sparked debates over the fairness of the format. However, as MLB continues to refine and optimize the system, the postseason structure has gradually become a classic format, widely accepted by most fans.