Sentence:  Essentially, punters who played the placecards — usually in a local pub — had to pick a <WSD>placegetter</WSD> in each of the four feature races on a Saturday. So, if it was races five, seven and eight, you had to correctly select just one of the three <WSD>placegetters</WSD> in each race to win. 
Meaning of the word marked with <WSD> tags:  A horse that finishes among the first three of a race, or in a specified place.