Connections and contacts are very powerful tools to get into residency programs.
The US Health Care system is built in a way so that personal recommendation from someone you trust will have great impact.
So if you have somebody in a residency program who can recommend you that would have a great impact.
However, there's no hard rules here. I will give you two examples to explain the situation.
Example 1:
Candidate got 99 and 99 in both steps. He's IMG and he has second attempt in the CS exam. He knows a resident in a program. That resident went and talked to the PD. The PD agreed to send for an interview (despite the fact that that program does not send for IMGs who have second attempt in the CS). Eventually they liked the candidate too much in the interview and they matched him.
Example 2:
Candidate got 82 and 85 in both steps. He's IMG and his CV is wonderful except for his low scores. He knows somebody who knows the PD of a great program. The PD refused to send him for an interview because he is so determined not to send for IV for anyone who has less than score 90.
So connections can help to get your file be seen by the PD or the selection committee but there's no guarantee that you will be sent for an IV if the PD is strict and does not go by personal recommendations.
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