>>536817314
>I have to put things in terms of math otherwise my brain can't process it
Okay, its like this anon.
When you see all 4 of one tile, you know there are none left in the wall/your opponents hands, so your opponent's wait cannot be a sequence containing that tile. Most defense theory is based on the opponent preferring a ryanmen wait because it waits for the most available tiles. So for example, if you see 4 3m on the table, you know the opponent cannot have 34m or 23m. Therefore, 1m and 2m are thus safer discards. They aren't absolutely safe, your opponent could have a tanki or shanpon wait on that tile, but they are safer than other tiles as those waits are less common. So when you see all of the 7 or 3 of a suit, tiles outside that, 89 and 12 are much safer than normal. Use this in combination with other things to decide whether or not a tile is safe to discard. To give another example, if you see 4 3m, and 2 2m discarded, the only possible winning wait for the 2m in your hand is 2m tanki, because there are no 3m sequences and not enough of the same tile to be shanpon.
This applies to all tiles you see, not just tiles discarded. If you have all 4 of the 3m in your hand, you know 3m is kabe, but your opponents don't.
