QUOTE(joeblows @ Feb 15 2013, 02:40 PM)
Nope.
The lower portion of the Bench Press works the pectorals more, the upper portion (last 25% of the rep near lockout) works delts more. That's why some coaches make very effective use of partial reps to failure.
Triceps does more or less work depending on grip distance and bar placement. Wider grip = less tri more pecs, closer grip = more tri less pecs. Lower bar = more tri less pecs, Higher bar = less tri more pecs. In fact guillotine press (placing the bar just under the neck with wide grips) is one of the best exercises to stimulate pec development but prepare to drop your weight waaaaaaaay down.
Inb4 some people gonna cry broscience, check with Uncle Google and do your own experiment in the gym if you don't believe.

When i just started lifting, i did guillotine presses for chest, but it worked my shoulders more than my chest.
i did a lot of research about lifting, i always end up getting more confused, there's always different theories advocated by different reputable trainees that has good results to show for, nearly all of them has good scientific basis in being the "best" way. HIT, GHVT, HST, 5x5, 3x5, high rep, different splits, full body, upper lower, push pull, different frequency 3 day, 5 day, 2 day a week. Too many factors like recovery rate, diet, rate of protein synthesis, hormonal response, different forms stimulating different muscles in different intensity.
that's why i think at the end, it's really up to self-experimenting and to find out what's best for you, there's no universal method in getting the most gains, only some basic principles like, progressive overloading, below 90 sec TOT for hypertrophy, weight gains = calories in vs calorie out. but even in those principles there's many variables, such as the poundage increase can be more of a neurological adaptation rather than a muscle growth.
regarding in lifting techniques and form, people are built differently, yeah there might be studies out there showing the best exercise for maximum muscular activation using EMS, but the population that participated in those studies aren't large enough to represent all of us, there is simply too many variables to draw any absolute conclusion about the human body. That's why like most bodybuilders, kai greene, jay cutler, their forms are sometimes weird, a lot of times we see them doing partial reps, bodybuilding isn't so much about the lifting technique, it's about muscular stimulation, mind muscle connection, if jerking only a few inches in the bench press allows you to feel like you have your chest muscles fully working, then to me it's fine, given that the form won't cause any injuries.
sorry it's a little long