It seems more often than not that the fresher horses who skipped the Derby aren't as likely to win the Preakness than a Derby horse. Rachel Alexander was the exception. The Belmont is a different story because, to win the TC, a horse has to run 3 times in 5 weeks. So a fresher horse or a Derby horse that skips the Preakness has a better shot at it than a horse that runs in all 3 TC races. This why the TC is almost out of reach to most of the horses.
Has there ever been a mare/filly to win the triple crown