The pectorals are the centerpiece of a well-developed bodybuilding physique. They make the connection between the other elements of a quality physique: the abdominals, the traps the deltoids and the arms.
Being the centerpiece that it is, the importance of achieving total development for this musclegroup is absolutely imperative. This goal, however, might not be quite as easy to attain as one would reckon at first glance. A complete and spectacularly developed set of pecs takes quite a bit of hard work and several assets: a great looking ribcage (remember this is what the pecs sit on so its importance can by no means be ignored), great thickness, a well visible separation between the upper and the lower sections of the musclegroup and a thorough development of both the inside and the outside of the pectorals.
All this being said let’s take a closer look on what we were actually talking about so far: the muscles that make up the pectorals:
-the clavicular part of the pectorals (which ties in to the collarbone). These are the muscles that one uses to draw his/her shoulder forward and to push away weights in a 45 degree angle from the body in an upward direction. (this is already out of the reach of both the front delts and the sternal portion of the pectorals so it befalls to the clavicular part of the pecs to stand up to these tasks)
- the sternal part of the pectorals. (this muscle group ties in to the breastbone on one side and to the humerus on the other) This is the musclegroup that lets one execute plain benchpresses (on a horizontal bench) and do parallel-bar dips (when leaning forward while executing the reps) It is the largest of the muscles belonging to the pectoral-group.
- the subclavius. This one is a small muscle linking the collarbone to the first rib.
- the serratus anterior. It is a thin layer of muscle, which links the pectorals to the latissimus dorsi (the back) and which - provided it is fully developed- can look rather spectacular as it forms a few ripples much like the radiator of a car. Serratus anterior training should be taken very seriously during competition training. Quite like the intercoastal muscles these are a telltale sign to the judges that the person posing has not only achieved a substantial amount of mass, but that mass is quality material too.
As far as famous bodybuilders go - of whom we can make an example here - we need to mention Sergio Oliva. Despite the fact the he didn’t really do but one type of exercise for his chest, his development was spectacular due to the fact that he possessed great genetics. John Grimek also had great genetics that showed clearly in his awesome ribcage. In regards to definition, many great competitors possess awesomely striated pecs, but Franco Columbu’s separation between the upper and the lower pecs is probably without an equal.
Serge Nubret and the truly colossal Dorian Yates need also be mentioned here.
Smalltalk put aside,.let us see what one can really do to best develop the muscles of the chest, the types of exercises recommended and the way each of these specific exercises should be executed.
Quite similar to the shoulders, the muscles of the chest are trained using two basic types of exercises: the good old presses - which are at the foundation of muscular mass - and the flys, which in turn are isolation exercises and as such they help define and refine the striations and the separation between different parts of the pecs.
A curiosity: there seems to be an inter-dependency between the latissimus and the pectorals. It has been noticed that one can’t achieve a fully developed chest without obtaining the same result with the muscles of the back and vice-versa. This is probably the reason why there is an advanced training program that supersets pecs training and back exercises.

Pecs exercises that fall into the category of presses:

1) Presses using a barbell on a horizontal bench
2) Presses using a barbell on an incline bench
3) Presses using two dumbbells on a horizontal bench
4) Presses using two dumbbells on an incline bench
5) Presses using two dumbbells on a decline bench
6) Dips executed on the parallel bars

Isolation exercises also known as “flys”

1) Flys executed with two dumbbells on a horizontal bench
2) Flys executed with two dumbbells on an incline bench
3) Cable crossovers executed while standing
4) Cable crossovers executed while bent forward
5) Cable crossovers on a horizontal bench
6) Flys done on a machine

As iterated beforehand, the thorough training - through isolation exercises- of the serratus anterior is of utmost importance on competition level. Here are the exercises recommended to achieve just that:

1) Pull-overs
2) Pull-overs on a machine
3) Chin-ups done with a close grip
4) Crunches done while hanging