Zach T. is correct. Most important statements of his is "improve the weaker links" and" increase flexibility". PBN's also can improve the triceps contractions greatly, adding more strength to the bench. I know some will ask how can a overhead press help a front lying press, but it seems to for a lot of men.
Sort of like when the hip's, glutes and hams become more flexible, through stretching and other means, the squat will improve. Added to that some serious low back training like GM'ings or SLDL's to come close to ones potential on the squat. Heavy ab work included. Good Luck.