The core question
Compare the value and likelihood of your own win with the risk of dealing into an opponent's. A ready hand with a good wait is usually worth pushing; a slow, cheap hand is usually worth folding.
Situational factors
Dealer status, current standings, how many tiles remain and how dangerous the tile you must throw is all shift the balance. Near the end of a game, placement may matter more than points.
Practical rules of thumb
Push with a ready hand and a two-sided wait. Fold with a hand two or more tiles from ready against a riichi. In between, keep progressing only with reasonably safe discards.
Learning by review
Push-or-fold judgement improves fastest by reviewing your games — ideally with tools that show expected values — and noticing when you pushed too far or folded too early.
