Open as soon as you have valid melds totalling at least 101 points and a realistic path to finishing soon after.

Opening lets you start laying off tiles and racing to go out, but showing your melds also reveals information to opponents. If you can reach 101 comfortably, opening early pressures rivals, who risk the plus 202 penalty for never opening. However, if opening would strand you with many hard-to-place tiles, waiting a turn or two to strengthen your hand can be wiser. Judgement here separates strong players from beginners.