I thought Tony's revelation was pretty plain to see.

He kept losing in poker, he wasn't having good luck something was in his way. It was metaphorical of Christopher being in the way of his empire succeeding. After Chris was whacked, he was doing much better, he realized what was in his way. A cosa nostra empire cannot survive with the possibility of speech.

It goes with the saying, "lose lips sink ships".

"Any American who is prepared to run for president should automatically, by definition, be disqualified from ever doing so"-Gore Vidal
"Conformity is the jailer of freedom and enemy of growth"-John Fitzgerald Kennedy
"The reason the mainstream is thought of as a stream is because of its shallowness"-George Carlin