At least with a horse who is racing in the same race today as it did last year, then you could be confident that:

1) The trainer has set it for this race, or at the very least gives it a really good chance in the race. It's not all that often that you can be certain of the trainer's motives is it. This is half the battle?!

2) Although the horse may not show up as having those famous 'c' or 'd' next to it's name, you know it is suited to this race. The trainer has said as much simply by entering said mule.

3) It's previous run in this same race the year before doesn't have to have been a win, or even a top run. The fact that it's enetered again suggests the horse is a chance.

4) The camp will have learned by any mistakes it made last year, and the horse may be in better 'nic' for this year's event.