The sentence that follows "but also a more skilled player will improve more quickly" is what explains the meaning of "but also a more skilled player will improve more quickly"; i.e. the higher his complimentary skills, the faster he trains.
edit: underlined complimentary so you guys will better understand me.
Edited by darykjozef (12/29/2007 2:32:20 PM CET)
I did misunderstand you. Yes, the higher complimentary skills will make it easier to train the skill in question. However, I think you missed my two points:
1) Training the poor skill directly is much, much better than the complementary skill training you initially suggested (at least I think that's what you suggested).
2) Getting Atrocious level up to (for example) Mediocre is still a time consuming process and one which needs direct training to minimize the time needed.
I'm also not certain that Inside shot is considered complimentary to the SG skill set, either.