Everyone knows that Barry Bond's elbow protector gives him an advantage by allowing him to lean over the plate without fear of being hit. Michael Witte of Editor and Publisher says that is not the only advantage of the armor. Witte claims that the protector is literally a "hitting machine", hinged at the elbow, that allows Bonds to release his front arm on the same plane during every swing. Witte concludes that Bonds' armor "may have contributed no fewer than 75 to 100 home runs." Unfortunately, no evidence or reasoning is provided for this conclusion, and the total of 75 to 100 home runs appears rather arbitrary to me.
As a student of baseball – and currently a mechanics consultant to a major league baseball team -- I believe I have insight into the Bonds "achievement." I have studied his swing countless times on video and examined the mechanical gear closely through photographs.
For years, sportswriters remarked that his massive "protective" gear – unequaled in all of baseball -- permits Bonds to lean over the plate without fear of being hit by a pitch. Thus situated, Bonds can handle the outside pitch (where most pitchers live) unusually well. This is unfair advantage enough, but no longer controversial. However, it is only one of at least seven (largely unexplored) advantages conferred by the apparatus.