Admittedly, I know absolutly nothing about the actual historical facts behind this story, or about horse racing in general, but this seems like a huge handicap. Why would this horse be given such a large handicap? Can anybody who’s read the book or is familiar with the historical facts explain this?
Well, the whole idea behind the Handicap is that better horses are weighted (“handicapped”) so that they can run against lesser horses and still put on some kind of race.
IIRC, Seabiscuit drew consistently high handicaps because it was believed (probably correctly) that he’d run away – literally – with the race if he wasn’t weighted that much.
It’s actually an aspect of his greatness that a lot of people who don’t follow racing do not appreciate. Seabiscuit ran in a lot of Handicaps, and he almost always drew the high handicap, in many cases, as you point out, an astonishingly high handicap. And he still won.
Seabiscuit was given such a large handicap (officially known as an impost in horse racing circles) because the racing secretaries (the guys at the tracks who decide such things) thought that Seabiscuit was so much better than his competition that he had to carry that much weight to make the race fair.
There is a rule of thumb about how much a horse loses for every extra pound it has to carry. I don’t know it exactly so I won’t guess it.
Horses rarely carry that much weight anymore. I’ve seen horses carry 125, but that’s pretty rare. Most trainers just won’t enter their horses in races if they get assigned that weight.
In the Triple Crown races, all the horses carry the same weight.
Wasn’t this the case with Phar Lap as well? I remember in the movie they made a big deal about how his handicap kept increasing and increasing (as the others have said, to “even out” the field), yet he kept winning. Of course it was heavily implied that this practice eventually killed him, which has hopefully cut down a bit on the extreme handicaps.