I want to say first and foremost that Exotica is the best coals I've ever used, period! With that being said, I have used nearly 75 sticks broken into 4 pieces each (around 300 1/4 stick pieces) and I have had exactly 3 -1/4 stick pieces crack after heating and splinter. So on average 1 out of 100. I will say that if you leave them on the heat too long they get cracks all over the coal, but rarely ever break apart. I guess hearing all these people having trouble, I'm glad I bought 6 Kilo's when they first came out.