Gyakuten

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Discarded winning tile may not be enough for gyakuten.

Gyakuten 「逆転」 ("comeback") is when a player improves their placement during the last hand.

Knowledge of the points table is particularly helpful for pulling a comeback: it can help determine the needed tile composition, if you can open the hand, if you need to call riichi, and other key decisions. In any case, like most things in Mahjong, at least a little luck is required to win.

Strategy for oorasu

The term "gyakuten" normally applies to the last hand of the game. In the last round, once a non-dealer wins, the game ends, and placement is finalized. Therefore, even a 100 point difference can matter. Lower players must develop a hand that gives enough score to pass the higher ranked players. On the other hand, players with their desired standing must find a way to retain their position at the end of the game, either by winning the final hand or simply avoiding losing points.

Gyakuten is important because placement is itself important. Thanks to oka and/or uma, a player can receive a large bonus for rising up a rank. Conversely, players can lose a lot if they fall in rank. In some types of play, such as certain tournaments or tenhou.net's dan ranking, final placement is the only thing that matters.

Riichi

If an open version of a hand is enough to improve your placement, no matter how it's won, then open the hand for the extra speed. Similarly, if you can guarantee improvement with a damaten hand, then do that.

Riichi gives 1 han, plus random bonuses via ippatsu, ura dora, and/or mentsumo. If you're particularly lucky, a riichi-only hand can turn into 7900 points with riichi ippatsu mentsumo dora 1. You should try to guarantee a comeback without any bonus han. However, if you have no reasonable way to do so, go for a riichi and hope you get enough points. At the same time, opponents will be especially wary of a riichi in the last round, precisely because they don't want to lower their placement.

In some cases, the 1000 point riichi bet is enough to drop you down a placement. If you have another yaku, you should usually go dama. If you don't have a yaku, then riichi is still worthwhile if you have a good wait. Since the trailing player is only 1000 points behind, any win they make would be enough for you to drop down, so you should still try to win.

Score differences

In the last hand of the game, non-dealers will likely have only one chance to make a difference, so awareness of the point differences and the scoring table are key.

The following table displays the minimum han/fu value required to surpass a leading player at a given point spread. Note that as you take points from everyone when you tsumo, the required han/fu value for tsumo is lower than a non-direct hit ron.

Gyakuten table
Han-Fu Non-dealer Dealer
Tsumo Ron Tsumo Ron
Non-dealer diff Dealer diff
1-30 1400 1600 2000 2000 3000
1-40 & 2-20 1900 2000 2600 2800 4000
1-50 & 2-25 2000 2400 3200 3200 4800
1-60 & 2-30 2500 3000 4000 4000 5800
1-70 3000 3600 4600 4800 6800
1-80 & 2-40 & 3-20 3400 4000 5200 5200 7800
2-50 & 3-25 4000 4800 6400 6400 9600
2-60 & 3-30 5000 6000 7800 8000 11600
2-70 5900 7000 9000 9200 13600
2-80 & 3-40 & 4-20 6500 7800 10400 10400 15400
3-50 & 4-25 8000 9600 12800 12800 19200
3-60 & 4-30 9900 11800 15400 15600 23200
Mangan 10000 12000 16000 16000 24000
Haneman 15000 18000 24000 24000 36000
Baiman 20000 24000 32000 32000 48000
Sanbaiman 30000 36000 48000 48000 72000
Yakuman 40000 48000 64000 64000 96000

Note: direct hit rons are worth double. Also, make sure to apply honba and/or riichi bets as needed.

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