No Other Sport Fixes Attack Order
Soccer alternates sides at halftime; basketball and volleyball feature continuous possession changes. Only baseball assigns a fixed batting order where the home team always bats second. This structure is so fundamental to baseball's design that no serious rule-change discussion has ever challenged it. The reason lies in baseball's turn-based nature, which creates asymmetric information between the teams batting first and second.
Information Asymmetry - The Core Advantage
The team batting second knows the opponent's score before each half-inning begins. In the ninth inning, the trailing team knows exactly how many runs it needs; the leading team knows it can win by simply preventing runs. This information advantage shapes managerial decisions: the home manager can optimize pinch-hitter and pinch-runner deployment based on the exact deficit or surplus, while the visiting manager operates under uncertainty about whether the current lead will hold.
The Concept of 'Sayonara'
The walk-off victory is the ultimate expression of batting-second advantage. When the home team scores the go-ahead run in the bottom of the ninth or extra innings, the game ends immediately with no opportunity for the visiting team to respond. This asymmetry provides the home team with a psychological edge in close games: knowing they will have the last word encourages aggressive play. NPB data confirms that home teams win slightly more than 50% of games, statistically validating the structural advantage.
Historical Origins
Early baseball rules allowed the home team to choose whether to bat first or second. Most teams chose to bat second, and the convention eventually became codified as the default. The logic was that home teams, already benefiting from familiar surroundings and fan support, should receive the additional structural advantage of batting last, institutionalizing home-field advantage within the rules themselves.
The Japan Series Home-Field Question
Batting-second advantage amplifies in short series. In the Japan Series, the team hosting Game 7 holds both the crowd advantage and the structural batting-order advantage. This makes home-field allocation a perennial debate. Following MLB's World Series model, NPB now awards home-field advantage based on regular-season record, recognizing that the combination of fan support and batting-second privilege can influence a seven-game series outcome.
Is Batting Second 'Fair'?
The batting-second advantage is statistically significant but small, roughly 1-2 percentage points in win rate. Over a 143-game season with approximately equal home and away games, the effect largely cancels out. The advantage matters most in short postseason series. However, eliminating the advantage would mean eliminating the walk-off, baseball's most dramatic conclusion. The tension of a bottom-of-the-ninth, one-swing-from-victory moment exists precisely because of this structural asymmetry. A slight unfairness may be the necessary cost of baseball's most thrilling drama.