Shattering bats might look cool, but they're really dangerous for both the players and the fans. Why does that happen, and how come bats always seem to snap in the same way? Consider the following: baseball bats are made of wood, and being a natural material, wood has certain innate structural flaws. One of the most popular bat woods — ash — has porous holes that run along the grain (grain being those different coloured lines that result from a tree's growth rings). Lots of tiny holes creates weakness, and weakness can cause bats to break, which is why manufacturers put their logos perpendicular to the grain on ash bats.
However, Barry Bonds caused a boom in popularity in maple bats, which neatly coincides with the uptick in shattering bats. Maple has a totally different grain structure to ash, and although it has grain like any other wood, the weakest points in a maple tree run radially from the centre (think of someone chopping firewood). Because players were using the same grain-perpendicular striking surface, these maple bats turned into wooden shrapnel with staggering regularity.
Recently, bat-makers have started rotating their logos by 90 degrees on maple bats, as well as marking the grain on the handles. Bat breaks have gone down about 50 per cent as a result, making fans and players less prone to accidental spear-related injury. Which is always a good thing.