Watching his 18th fight against Favio Olivia he was very aggressive, showing a lot of power, with the commentator mentioning how he always fights like that. I always thought he was a defensive boxer like he is now. Did he change due to going up in weight (decreasing power), or something else?
He moved up and left his power behind, Floyd Snr turned him into a more defensive-minded fighter. He used to be a banger back when he used to fight at 122.
He fights like a banger when he can and retreats after he notices the other guy can take his punch and keeps coming. Thats when he turns into a defensive fighter.
He merely adjusted fighting style as he matured and went up in weight. His present trainer Floyd Sr. is big factor on this.