What is needed to have better chances for residency?

hi there

Can any one tell me in general , about what makes me able to get better chances on residency programs

scores in step 1 step 2 ck and step 2 CS and the correlations with the opportunities the residency programs offer

how can years after graduation affect my chances ?

If there are no available residency programs in the specialty I want, can anything increase my chances like getting a MD degree from efficient medical system (as in Germany ), I know that to be eligible for step 3 you should be graduate from ACGME approved residency program, but after taking step 1 and step 2 ck and step cs and not getting the residency i want is a dramatic scenario for me , i know that it seems that i have confused information about the residency programs , but i want to get sure about the decision to take USMLE and the possibility of wasting time and money

i am about to take the decision to begin preparing for USMLE , i want to make sure that it worth it