Horse Races at Del Mar, San Diego - Lens Choice

Will be going to the horse races at Del Mar, San Diego this afternoon. I think we'll be sitting in the grandstand but will probably leave my group and try to get closer to the action. I was thinking about bringing my 80-200mm Drainpipe but have access to the Canon 100-400mm (luckily I have two neighbors w/this lens).

Will the Drainpipe be enough reach or should I lug around the 100-400?

If you are in the stands I'd think you'd appreciate the extra reach of the 100-400. On the rail I'd think the drainpipe would suffice.

Exactly. Isn't it going to depend on how far you are from the horses

It's a work event so I'm assuming we'll be in the grandstand. I'll probably make my way down after the 1st race and try to get closer towards the rail. I've been the the fair tons of times but not the horse races.

I'll schlep my drainpipe & telecon and should be good to go.