Maximal Strength Method: Want to get strong?
Have to lift heavy...
Lifting maximal loads (at or above 90%) is considered superior for improving both intramuscular and inter-muscular coordination; the muscles the CNS adapt only to load placed on them. This method should be used to bring forth the greatest strength increments.
(See science and Practice of Strength Training (Zatiorsky 81).
As the human ability varies daily even hourly, predetermined percentages are an inferior tool for training maximal strength. Better measurements are being able to accurately monitor and assess bar speed, as well as communicating with the athlete as to his or her perception of the difficulty of the lift. All field athletes should be careful to keep their Max effort lifts to 90-95% - anything higher constitutes limit strength, which is useful only for strength athletes.
And remember: Max effort is not recommended for beginners. Only after proper technique for the exercise is acquired and the relevant muscles developed is it wise to lift maximal weights.