A credit fund manager once opined that the easiest way to make money was to not lose it in the first place. Others have expressed similar sentiments that in their simplest form can be explained thus: a firm is only as good as the credits it invests in.
A cornerstone of debt investing is, of course, doing your homework – conducting thorough due diligence and exhausting all available avenues that allow a firm to get its figurative arms around any given credit.