Gyakuten

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: 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.

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 mangan 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

With essentially the last hand of the game, players have one chance left to make a difference in the game. With that, awareness of point difference is key, which links directly to values from the scoring table. Here, minimal hand values are considered at the very least in order for players to surpass others higher in placement.

Using the values from the scoring table, a point difference can tell players which hand values are necessary to surpass a leading player.

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.