The Home-Run Bat in Super Smash Flash is the strongest battering item. Similarly to the official game, a connected smash attack with it will certainly KO the opponent. The player holding the bat can charge the smash attack and move around simultaneously; which allows for more precise aiming. Like most items in SSF, the bat has limited uses and disappears from the player's possession once it has been used a certain number of times; the longer the player holds the charge, the lesser the time the bat has before disappearing.
In Super Smash Flash 2
With further improvements, the Home-Run Bat in Super Smash Flash 2 is again the strongest of all battering items, now sporting a unique, custom design: it is a metallic bat with a dark grey grip and with the Super Smash Bros. logo below the end cap. Its function was changed to work like it does in the official Smash Bros. games: players are now unable to move and hold the charge, now only producing a single, delayed swing with their forward smash for a guaranteed one-hit KO if connected. Also unlike in the previous game, the player can just press attack to make a small attack on the enemy.
As with many items under the Super Smash Bros. category, the Home-Run bat has no defining origin game, but instead seems based on real-life baseball bats. The objective of baseball is to score "runs" by hitting a ball that is thrown by the opposing team's pitcher with the aforementioned bat, which is swung by the batter. Should the batter hit with the correct timing and angling, the ball can be sent out of the playing area or even out of the park, scoring what is referred to as a "home run", allowing the batter, as well, as any other players standing on the bases, to circle the bases and reach home safely in one play without any errors being committed by the defensive team in the process. The one-hit KO properties of the Home-Run Bat is directly based on this way of scoring.
It is theorized the Home-Run Bat may also be inspired by the critical hits from the EarthBound games. The protagonists of their respective games, Ninten and Ness, have baseball bats as their main weapons, with more powerful variants found in latter parts of the games. The aforementioned critical hits occur at random chances, allowing for more damage than ordinary attacks. Ness himself uses a common baseball bat as his forward smash in SSF2.