Why facing a left-handed tennis player is more difficult? Everything starts with the observation that the percentage of left-handed people in the world is about 13%, but in some sports, this percentage is much higher. First of all, it is assumed that left-handed players are more used to competing with athletes who use the right hand, but the opposite is not true.
So the reverse position of the lefties confuses opponents, who are often unable to anticipate the other player's moves. The superiority of the left-handers, however, is manifested above all in those sports where the pace is more frenetic and the speed of reaction is a crucial element.
Florian Loffing wrote an article entitled Left-handedness and time pressure in elite interactive ball games, to try and answer this question. He collected statistics on the top 100 left-handed athletes in six sports in the period 2009-2014: tennis, table tennis, squash, cricket, baseball and badminton.
Following an abstract of his study: "According to the fighting hypothesis, frequency-dependent selection gives relatively rarer left-handers a competitive edge in duel-like contests and is suggested as one mechanism that ensured the stable maintenance of handedness polymorphism in humans.
Overrepresentation of left-handers exclusively in interactive sports seems to support the hypothesis. Here, by referring to data on interactive ball sports, I propose that a left-hander's advantage is linked to the sports’ underlying time pressure.
The prevalence of left-handers listed in elite rankings increased from low (8.7%) to high (30.39%) time pressure sports and a distinct left-hander overrepresentation was only found in the latter (i.e. baseball, cricket and table tennis).
This indicates that relative rarity and the interactive nature of a contest are not sufficient per se to evoke a left-hander advantage. Refining the fighting hypothesis is suggested to facilitate prediction and experimental verification of when and why negative frequency-dependent selection may benefit left-handedness.
Fitness benefits are predicted for duel-like situations where unfamiliarity with left-handers may directly affect performance. Sport data support this notion in that left-handed athletes are found overrepresented in the high echelons of interactive (e.g.
cricket, baseball) but not non-interactive (e.g. darts, snooker) professional sports. For each sport, data were collected for six seasons (2009–2014) to account for assumed temporal variation in left-hander frequencies.
For each racket sport, the top-100 players from the official year-end world rankings were retrieved. For cricket, data on the top-100 Test bowlers listed in the official ICC player rankings were considered. As no world rankings on individual players were found for baseball, ranking data for the top-78 to 94 (depending on the year) pitchers in Major League Baseball (MLB) were taken.
Time pressure was defined by the mean time interval (in milliseconds) between the actions of two interacting players in male competition. In racket sports, the time between moments of racket-ball-contact was recorded. In baseball and cricket, the time elapsed from ball release to (estimated) bat–ball-contact was considered.
Generally, shorter intervals characterize heavier time constraints. Restriction to racket sports did not alter the effect: left-handedness was more likely in table tennis than in the other racket sports combined and when compared with each sport separately.
No notable differences were found between badminton, tennis and squash." Source: Left-handedness and time pressure in elite interactive ball games by Florian Loffing