Haven't played too many rounds here yet but I've won every single ranked match. Splat zones, for those wondering. And I credit it to this wonderful Sprinkler location:
A Sprinkler here can take the entire zone by itself. Of course you can help it along by shooting the ground as well, but left to its own devices it can capture it for you in about 10-15 seconds depending on how the ink blobs fall.
But the best part is that if you place it on the enemy side of the map, then they seem to have limited options to easily get rid of it. A charger on the far platforms behind my Inkling's head could probably reach, and specials are always an option. But other than that, I'm not sure what recourse they have without having to enter the splat zone itself, which seems like a rather vulnerable position to be in.
My tactic was simply to get that Sprinkler in place and try not to die. I still died a few times, but luckily my team was able to keep up a solid presence until I respawned. The only time I noticed it gone without me dying was after a Killer Wail and Inkzooka ripped through the area, so it probably got smashed by one or the other.
So...yeah. The zone is also small enough to get captured by a single Inkstrike, which will probably prove to be quite irritating since that can force an instant penalty timer.
Other, unspecific observations:
You can jump most of the gaps as a kid, although it's a close thing. It's easier as a squid for obvious reasons. Run/Swim Speed Up help in general.
The water level changes "halfway" through the map. In turf war, that's simply 1:30 into the match, easy enough. To help out, there's 10 seconds of chimes and the resort windows flash in order to warn players. In Splat Zones, it's either 2:30 into the map
or when one team or the other first reaches 50 points, whichever comes first, and there is no warning before it happens so keep an eye on the timer and clock. In Tower Control, the water level drops as soon as the match begins. Not sure about Rainmaker.
(Also, hi! New to these boards. I guess this is as good a first post as any.)