286 LIGHT SCIENCE FOR LEISURE HOURS. 



the initiated, they offer them and in general success- 

 fully to the inexperienced. 



It is often said that a man may so lay his wagers 

 about a race as to make sure of gaining money which- 

 ever horse wins the race. This is not strictly the case. 

 It is of course possible to make sure of winning if the 

 bettor can only get persons to lay or take the odds he 

 requires to the amount he requires. But this is precisely 

 the problem which would remain insoluble if all bettors 

 were equally experienced. 



Suppose, for instance, that there are three horses 

 engaged in a race with equal chances of success. It is 

 readily shown that the odds are 2 to 1 against each. 

 But if a bettor can get a person to take even betting 

 against the first horse (A), a 'second person to do the 

 like about the second horse (B), and a third to do the 

 like about the third horse (C), and if all these bets are 

 made to the same amount say, WOOL then, inasmuch 

 as only one horse can win, the bettor loses 10007. 

 on that horse (say A), and gains the same sum 

 on each of the two horses B and C. Thus, on the 

 whole, he gains 1000/., the sum laid out against each 

 horse. 



If the layer of the odds had laid the true odds to the 

 same amount on each horse, he would neither have 

 gained nor lost. Suppose, for instance, that he laid 

 1000Z. to 500Z. against each horse, and A won ; then 

 he would have to pay 10007. to the backer of A, and 

 to receive 5007. from each of the backers of B and C. 

 In like manner, a person who had backed each horse 



