Why do Baseball Bats Break?

I turned a birthday gift for my brother this week, and decided to make a video about a relatively recent change in the MLB's rules governing wooden baseball bats.

In 2009, the MLB health and safety advisory committee determined that the increase in the use of Maple baseball bats (over the traditional ash bats) was a primary reason for the similar rise in bats breaking during games. This had to do with the engineering properties of the two different woods, and how manufacturers were grading bat blanks. The committee issued a series of recommendations to reduce the occurrence of breaking baseball bats, including improvements to how maple blanks are graded. The recommendations have reduced the rate of bat breaks by about half.