Paul determines the names of the winning horses by riding his wooden rocking horse. If he can ride his horse until he "gets there", he receives a kind of revelation so that he is "absolutely sure" which horse will win the next race. It is a frightening experience when Paul rides to this extent, because he urges his horse on with an intensity which borders on frenzy, "madly surging", seemingly possessed by a strange, inner power. Paul is never wrong, however, when he is "sure"; and it is in this manner that he was able to predict that the longshots Daffodil and Malabar would win the Lincoln and the Derby, respectively.
Paul does not always pick a winner - "sometimes (he) (has) an idea, and sometimes (he) (hasn't) even an idea". Then, when he is not "absolutely sure", he "mostly go(es) down", betting wrongly and losing money. After he was correct about the Lincoln, he took a chance on the Grand National, but because he had not really "known" which horse would win, he had lost a hundred pounds.
Paul learned about horse racing from Basset, a young gardener who is "a perfect blade of the 'turf'...he live(s) in the racing events". Paul had come to Bassett and asked what he knew about horse racing, and Basset had lent him his "first five shillings, which (he) lost". Bassett is so involved with racing that he speaks of them "as if he were speaking of religious matters".