DAILY MAH-JONGG
By Tom Sloper

Monday, May 12, 2003

Column #37

Chinese Official (CMCR). There is a basic defensive strategy that works for all the Asian forms, by which I mean all the forms excluding American (even including Western mah-jongg). It's called the 1-4-7 principle. It works for those "un-American" forms because it involves chows (which are not and haven't been part of the American game since the late 1930s).

The 1-4-7 principle works mainly in Japanese Modern and Chinese Official, both of which require the player's discards to be placed in orderly rows (rather than haphazardly on the discard floor). And it works best in Japanese Modern, in which a player may not win on a tile he has previously discarded.

Most tile groupings in a mah-jongg hand are chows, and most incomplete groupings are incomplete chows - two sequential numbers, awaiting a third (usually at either end).

The numbers 1 and 4 and 7 are each two numbers apart. If someone has a 2-3 in the hand, that player is waiting for a 1 or a 4 to complete it. If someone has a 5-6 in the hand, the player is waiting for a 4 or a 7 to complete it. According to the 1-4-7 principle, then, when you see that a player has discarded a 4, the 1 and the 7 of that suit are reasonably safe to discard. This principle also applies to the numbers 2-5-8 and 3-6-9. For more on this principle, see the book by Eleanor Whitney.

Wei-Hwa was working on Seven Pairs. Noriko had 234D and three flowers. Earl had 678C, and two flowers. Samantha was showing 456D, with two flowers. Wei-Hwa had no exposures, of course (and no flowers). He had a quandary about what to discard.

He had to throw either 3D or 5B. One might be deadly to throw. He checked the discards.

Applying the 1-4-7 principle, 3D ought to be safe as far as Samantha (only) was concerned. 5B was reasonably safe as to Earl and Samantha both. Both tiles were possibly dangerous as far as Noriko was concerned. 5B seemed slightly less dangerous, and he wasn't ready to give up the hand, so that's what he threw. Nobody took it. His next pick was 4B, which (according to the 1-4-7 principle) was safe all around. So he threw that. His tension increased when Samantha punged W from Earl. Then he picked 3D. He credited the 1-4-7 principle for this one.

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