One thing to remember is that, unfortunately, its not at all uncommon for an increase in the breakdown/injury rate when horses move to a new track, regardless of the surface they were going to and coming from.
I have had that unfortunate experience with many of my horses and it just happended to me again 3x over in the recent moves from Churchill to the Spa and Hollywood to Del Mar.
I have a foot bruise, a hind end muscle pull and a quarter crack respectively all within days of these 3 horses shipping to their new tracks.
Like Jerry talks about with the impact of big efforts causing a change in stride legnth, etc and that leading to injuries, it\'s easy to understand that a horse picks \'em up and puts \'em down differently when they get onto a new surface and that causes these injuries.
Fortunately for me this time, none of these are all that serious but I have had leg fractures, etc before in these same transitions.
What I think this really argues for is a quasi-European type model where the horses train offsite at the same location year round and then ship to the track only to race.
It\'s still very hard to defend that surface at Del Mar. Horses seems to struggle over it unless the temperature and watering (and tides probably) are just right, which is rare. Racing is just so ugly to watch there. And you need to handicap the horse who will still be standing at the end of the race. You don\'t want to go out too fast, but you really can\'t close in that goo either. It\'s an absolute disgrace. But like so much of American society, the emperor has no clothes and no one gives a crap!