Caribbean schools get bashed so much on this site. If you study hard you can make it through. Although this is a biased sample but EVERY single one of my fb friends who decided on Caribbean are doing just fine and the ones who graduated matched back in the states. These people were not special by any means (partied it up in undergrad).
Look, here's the thing.
If you make it to graduation, you have about a 75% placement rate from the caribbean schools.
In terms of sheer odds, that's not bad. It's also why you hear so many anecdotal success stories.
However, that number needs to be looked at through the proper perspective:
1. That 75% number is only for people who make it through. SGU has, based on various sources online, 25-30% attrition. Ross has more like 40-50%, same for Saba, maybe more for some of the other schools. The schools don't directly report those numbers but this has been gleaned from numerous journals/reports/lay press articles over the years. In contrast, the attrition rate in US schools is typically <5%.
2. That 75% number is really only for primary care fields. For EM (a reasonably but not insanely difficult specialty for a US student to match into), the IMG match rate was 30%. For the super competitive fields like ortho, there aren't even high enough numbers to report data on.
3. That 75% number is, largely, made up of programs that US students don't even apply to. There are certainly exceptions to this but that is the most common.
4. Even if we ignore (1-3), let's revisit that 75% number. While 75% may not seem "bad", the flip side of that is that you have a 1-in-4 chance of spending 4-6 years and accumulating 6 figures of debt and not having a career at the end of it all. If a US school - MD or DO - had a 75% placement rate, it would be shut down. Collectively, US MD schools have a 95% match rate and a 98% placement rate (placement includes the match and the soap/scramble). DO schools similar.
5. When a US student goes unmatched, the most common reason for this is that they were applying for a competitive field such as derm or ortho (out of the unmatched US students this year, about half of them were applying for uber competitive fields). While this sucks tremendously to not match, the ultimate long-term fate of these students is not that bad. They were at least decently competitive students in the first place to even be applying for ortho, etc in the first place. So they either snatch up the good spots in the SOAP, or they reapply the following year with a different strategy in the match. The fate of an unmatched US student is much kinder than the fate of an unmatched caribbean grad.
TL;DR:
IMG: 75% chance of a residency if you manage to graduate + 30-40% attrition rate = when you enroll in the school you have a 50% shot at making it.
US-MD (or DO): 98% chance of a residency if you manage to graduate + <5% attrition rate = when you enroll in the school you have a 95% shot at making it.