Toitoihou: Difference between revisions

(put compat at 2= for consistency)
 
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=== Viability ===
=== Viability ===
Naturally, this yaku is reasonable if your hand contains many triplets and/or pairs. Note that toitoi looks easier than it actually is. There are only 2 possible tiles that can turn a pair into a triplet - there are 4 copies of a tile in mahjong, and 2 are used in the pair, leaving 2 tiles that can make the pair into a triplet. Meanwhile, a [[ryanmen]] joint can be turned into a sequence with 8 possible tiles. While you have access to pon to turn pairs into triplets, your opponents might not discard the tiles you need to pon in the first place. The tiles could be in the [[dead wall]], or they could be used in another player's hand.
Naturally, this yaku is reasonable if your hand has many triplets and/or pairs. Note, though, that toitoi looks easier than it actually is. There are only 2 tiles can turn a pair into a triplet (4 tiles in mahjong; 2 are already in the pair). Meanwhile, a [[ryanmen]] can be turned into a sequence with 8 tiles. While you can pon to turn pairs to triplets, your opponents might not discard the tiles you need to pon. The 2 tiles could be in the [[dead wall]], or used in an opponent's hand.


Pairs made out of middle tiles (tiles from 3-7) are particularly hard to pon. Because the middle tiles are likely to be kept in an opponent's hand, they are hard to pon. If you have multiple pairs made out of middle tiles, this yaku becomes slower to complete.
Pairs made out of middle tiles (tiles from 3-7) are particularly hard to pon, because middle tiles are more likely to be kept in an opponent's hand. If you have multiple pairs made out of middle tiles, this yaku becomes slower to complete.


In addition, a hand with many pairs can also form [[chiitoitsu]]. The (very rough) rules of thumb are:
In addition, a hand with many pairs can also form [[chiitoitsu]]. The (very rough) rules of thumb between toitoi and chitoitsu are:
*If you have 4 pairs and one turns into a sequence or triplet, you should probably go for a regular hand structure. This may or may not be toitoi.
*If you have 4 pairs and one turns into a sequence or triplet, you should probably go for a regular hand structure. This may or may not be toitoi.
*If you have 5 pairs, you should likely go for chiitoitsu. Keeping the option for toitoi is fine (e.g. 4 pairs, 1 triplet, 2 lone tiles. The hand can turn into chiitoi if you discard the triplet, can toitoi if you pon) so long as the pairs are reasonable to pon.
*If you have 5 pairs, you should likely go for chiitoitsu. Keeping the option for toitoi is fine (e.g. 4 pairs, 1 triplet, 2 lone tiles. The hand can turn into chiitoi if you discard the triplet, can toitoi if you pon) so long as the pairs are reasonable to pon.
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