Anyone who thinks this is dumb or not thread-worthy has obviously never played basketball at a competitive level.
It's not the "level" of fanciness or trickery that is the interesting part. He's not gonna slide around and do tricks like the Harlem Globetrotters.
Right before tipoff, your heart is racing a million miles an hour and you get butterflies in your stomach, and you need something to calm your nerves.
This is Rondo's way of doing that, and it's unique and really cool that he's got something small to take the edge off and get him into his routine.
There is a psychological method that all athletes learn called "Reduction of Significance" or other similar names to that, meaning if you play down the event in your mind, it can help you focus better, be more at ease less nervous. This is Rondo's way of reducing the significance of the start of an important game.