Undefeated Entering The Derby

[Smarty Cide]

Anyone know what the record is of horses undefeated entering the derby?

[salty]

http://www.drf.com/news/kentucky-derby-top-five-contenders-and-other-statistics

There are a few different statistics here.

undefeated
horses that did not start at 2
derby winners best pre derby beyer, final prep beyer and winning derby beyer

[nijinski]

I believe Seattle Slew remains the only undefeated Triple Crown winner.

[School of Forego]

I believe Seattle Slew remains the only undefeated Triple Crown winner.

And Gemologist is the only one with a chance to join him. It's been too long. I know it's getting way ahead of things but after the derby it won't look like such a pipe dream.