It's not a style choice at all really. If you have ``` X LEFT Y ON Z WHERE W ``` If the conditions are in the `W` clause they will reduce the number of rows returned from `X`. If the condition is on the `Z` clause then all the rows of `X` will be returned even if some of the `Z` conditions fail. You'll get nulls. So the `W` doesn't participate in the "leftness" of the join. In this particular case there were 4 joins and all of the `X` were desired regardless of the join conditions, so all the conditions must go in the `ON`. `ON` is equivalent to `WHERE` only for `INNER` joins.