2-05Meld a Prime Chow to build Mixed Straight
The 123, 456, and 789 chows are called prime chows. Melding only prime chows gives your hand flexibility. That way you can change plans down the road if the tiles required for your hand go dead. In addition, it gives opponents less information.
Figure 1
Does this player need 
to complete Mixed Straight?
chow
chow
For example, take Figure 1. Despite the fact that the player has melded two chows, it is difficult to pin him on a hand. It may appear that he is building Mixed Straight and needs to complete chow, but he may in fact have the hand shown in Figure 2.
Figure 2
As it turned out, the player was going for either Pure Straight or the 789 Mixed Triple Chow
chow
chow
His hand appears to be Mixed Straight, but could in fact be any one of Mixed Triple Chow, Mixed Shifted Chows, All Types, Outside Hand, or Pure Straight. When an opponent melds such chows, it is not possible to determine what tiles he may need or what combination he is building, so it is usually best to proceed as normal and build your own hand as fast as possible.
Figure 3
Meld 
into 123 and into 456 in order to leave the 123-234-456, 234-345-456, and Mixed Straight possibilities all open
If you are building a Mixed Straight with a hand like the one in Figure 3, you should meld prime chows as much as possible. By doing so, you can retain the Mixed Straight possibility while simultaneously leaving outs open for other combinations, such as Mixed Shifted Chows. Meld chows that will form the core of your hand, then adjust accordingly depending on what tiles you pick. You will find that when your Mixed Straight fails, one of your backup combinations is likely to work out instead.
Figure 4
gives the player Mixed Straight, and gives the player Chicken Hand (note: the latter cannot be self-picked)
chow
chow
Also, keep in mind that it is often make ready on both Chicken Hand and Mixed Straight. In Figure 4, gives you Mixed Straight, and (provided that it is taken from a discard) gives you Chicken Hand.
 |
 |
 |
