Lay Betting Explained. Lay betting (also known as lay bet matching, arb betting, double betting and matched betting), is a betting technique used by individuals. Beginners Guide explaining the concept and benefits of horse racing lay betting. Making money from losers with online betting exchanges like Betfair!. Bet -Types explains what lay betting is and provides an example of a lay bet. Bet - Types also tells you which Bookmakers offer lay betting.