Play: In a game versus Iona, Fordham rallies from 9-1 down to tie the game. With the score tied at 9 in the bottom of the 8th and bases loaded, Fordham goes ahead with game-winning hit. The base runner at first scores by leaping over the Iona catcher and landing on home plate with a handstand, to put Fordham ahead 12-9, which was the final score.
Ruling: If this incident were to take place in a MLB game, the MLB Rules do not discuss the case of runners leaping over defensive players attempting to make a play on them. MLB rules cover when a base runner runs more than three feet away from the baseline to avoid being tagged. Past practice and generally accepted interpretation concerns running outside the baseline left or right, not up-and-over. In this case, and until the MLB Rules cover somersaulting over defensive players by base runners, the base runner in a MLB game would not be declared out.
By contrast, the NFHS Rules prohibit base runners from “jumping, hurdling, and leaping” over fielders unless the fielders are “lying on the ground.” The NFHS Rules also specify that “diving over a fielder is illegal.” Consequently, a high school player who somersaults the catcher in an attempt to avoid being tagged would be declared out by the covering umpire.
Sources: MLB 7.08 (a); NFHS 8.4.2 (b.2)