If you are a novice player in craps, then we would provide with a very straight forward advice. You have to do everything to stay away from the crap bets termed as Hardways bets and avoid placing any amount on them. However if you really want to understand the game of craps then it is important that you have a better understanding of how you can avoid these bets. When playing craps, it is possible for a player to attain a total of 6 in a number of different ways. You can get 6 in any combinations like (1, 5) (2, 4) (3, 3) (4, 2) and also (5, 1). It is possible to obtain a total of 6 by pairing in one way and without pairing in four different combinations. As the probability of getting 6 by pairing is less, so, this way is generally termed as the hardways. The other combinations are called as rolling 6 the easier ways. So when you obtain the total of 4, 6, 8, or 10 by making pairs then it is termed as hardways.
When placing the bets for a hardways 4, it is obvious that a player should get the pair of 2s to obtain four before he can obtain 4 the easier ways or before hitting 7. In case the player manages to roll any other number then the bet is simply carried forward to other player in the row. This same principle is considered when trying to obtain a hardways 8 or even 10.
So I feel that most players may now be able to understand why they should avoid placing bets on the hardways. The example of getting hardways 4 is always considered as the first option. A player may lose his bets if the number 7 rolls first or even if the total of 4 is obtained the easier way. The number 7 can also be rolled in 6 possible ways like (1, 6) (2, 5) (3, 4) (4, 3) (5, 2) and (6, 1). Rolling a four the easy ways has two options (1, 3) and (3, 1). So when placing hardways 4 bets, players can always loose in eight different ways and the only way to win hardways four is one (2, 2). As players can loose this bet in eight possible ways and win in only one possible way so the winning ratio of correct odds is 8:1.
Now having a look at the hardways 6, players may lose this bet in case 7 rolls up before hardway eight. To roll 7 we already know that there are six possible ways and four different ways to roll an easy way six. Players can lose this bet in ten different ways and win in only one way. Here the correct odds are in the ratio 10:1. As most casinos pay only for 9:1 so the house edge is around 9.1%. In the same way you can also do the calculation for hardways 8.