Balancing Gangplank
Just some thoughts on GP's kit. I'm not a high level player and I don't even play it anymore due to my work load but I do watch the games when I can and study the patch notes and pro-level play (mostly LCK).
GP E is his main source of damage. Or rather Q on E. Multiple E casks. His E has a 1000 range which sounds OP except that it's gated by this 625 range Q. Or is it?
Place a barrow 325 range of you (so you can press Q and set it off). Then wait for it to get to 1 health (or just about). What's your opponent gonna do? There's no counterplay at this point (unless they flank you). They can't auto it (even Caitlyn can't). If they come close (650) you just place a max range E and then shoot the barrow off. It's impossible for them to auto it before you deal the last hit and damage them. The other option is to not get close to those barrels but then you just place an outranging 1000-range E and blow up the barrow beside you.
Or leave. And lose the objectives. Why not nerf his E range? That changes his gameplay to more kite-oriented. He has to place smart barrows (in brushes) and bait the opponents into a massive AoE damage. You can try to lower the barrel connection range from 650 to 400-500 but that doesn't really change it too much because in the scenario I gave but it is warranted regardless. It also matches up nicely with the explosion radius and helps players understand all the zones (kind of confusing that they're not the same).
I have a suggestion for a more interesting E mini-game. Two changes: 1) E cask explosions only lower 2 health per barrel hit and 2) barrels tick twice in it's lifetime. Barrels only explode if GP has the last hit, otherwise, it fizzles out. This does mean that if the enemy autos it at least once, GP is forced to respond (removing passivity). This creates the chicken game that you guys said there would be. Basically, if the enemy autos it, then GP just has wait for it to tick and then Q it before the enemy can auto again. Or they wait till it ticks once and dare each other to auto it. Whoever autos first, loses. But wait too long and whoever autos first wins. That's the game of chicken. Then you throw in other barrels and it becomes chaos. At 2 health whoever hits it first wins but if GP hits another connecting barrel first, then he wins (reversed). That's just so much more exciting than right now.
The current iteration is just who can hit when it reaches 1 health, time it perfectly. There's no mind games or psychs. It's all in GP's ballpark. It's an illusion of choice. The right choice is not to auto the 1 health barrel, he'll just Q it before you can auto it - or if you're ranged, place a barrel near you before you can reach the range to auto it. And with the E chain reaction regardless of health, it means that GP's can just set up barrels AFTER they leave one near them with 1 health and just chain explode them all.
You can balance around that, just like any champion. But there's not as much mind game opportunity. I think there's a huge opportunity here that's being missed. I don't think GP is a very interesting champion. I think he does require skill but it's skill like any other champion with ground-targeted abilities, of which he only has two. Please make his main source of damage have more counterplay or decision making around it. I hate watching GP in pro-level matches, there's little nuance in it. It's just "don't walk into 650 range of a 1 health barrel or zone him out of that barrel".
tl;dr barrels need more counterplay! You can have mind games if you just make two changes. Read above, sucker, there is no tldr