Sakigiri

Sakigiri 「先切り」 is the act of discarding potentially dangerous tiles early. This strategy generally sacrifices tile efficiency for the sake of defense (but still aims to reach tenpai, at least at the start).

Usage

When playing for maximum tile efficiency, it is best to keep useful tiles before useless ones. However, those tiles tend to be dangerous as the hand progresses. The idea behind sakigiri is to discard dangerous-but-useful tiles before opponents reach tenpai, to have a better chance of defense later on.

Conditions to/not to Sakigiri

Evaluate the tile acceptance and danger level of the tile you want to sakigiri.
- For example, in a 135-pin shape, keeping the 5-pin is normally good. However, if 3/4 of the 4-pin have been discarded, the 5-pin only adds 1 tile of acceptance. This makes 5p a dangerous tile that contributes little to the hand, so sakigiri 5-pin.
- 4/5/6 tiles are especially dangerous when compared to other tiles.
- Also, consider the safety of the useless tile. Guest winds are safer than normal, but they are only 100% safe when all 4 copies of that wind are visible.
Situational analysis: Your placement and the current round # should be important factors for sakigiri. When far in the lead and in the late game, prefer to sakigiri, since it can be afforded. Conversely, when winning is the #1 priority (e.g. last when late in the game), don't lose out on efficiency.

Reasons to prefer not to sakigiri:'

Don't sakigiri with a good hand (fast and/or valuable), especially when early in the game. When winning is feasible, aiming for the win is often the best move. In an even gamestate, prefer 4 tiles of acceptance over a safe tile.
Don't sakigiri if the hand has <5 blocks, or if the hand is at least 3-shanten. Keeping good tiles here is more valuable than normal.

Examples

All else equal, discard tiles that are more dangerous first

Draw:

The 7-pin and West are equally useless here. While number tiles are normally stronger than winds, the hand doesn't benefit from having the 7-pin. The hand is already at iishanten, so when it reaches tenpai, the 7 will be discarded. Further, the hand already has good joints; the joints do not need to be upgraded. Therefore, both 7-pin and West are equal for tile efficiency. In an average gamestate, 7-pin should be discarded first, because it is a more dangerous tile than a guest wind. (The earlier it is, the less likely it is to deal in.)

This is not a true case of sakigiri, but it does demonstrate the principles of sakigiri: dangerous tiles are better to discard early. Generally, if a hand already has 5 good blocks, it's ok to discard lone middle tiles.

When winning doesn't matter / is unlikely

Draw:

This hand is cheap and slow, though it has a yakuhai triplet, so there's a chance to complete via calling. Still, because the hand is poor, going 100% offensive is less effective. Especially when you're past the first few turns, you can consider keeping the West as a safety tile.

Sakigiri to confirm yaku / dora

Draw: Dora Indicator: