Complex sentence: Later that month Mont Tremblant started at odds of 18/1 for the 1953 Grand National in which he carried top weight of 153 pounds and finished second, twenty lengths behind the Vincent O'Brien-trained Early Mist.
Split into simpler sentences: Later that month Mont Tremblant started at odds of 18/1 for the 1953 Grand National in which he carried top weight of 153 pounds. He finished second, twenty lengths behind the Vincent O'Brien-trained Early Mist.