Since there always is a lot of crying about every change to BBs (either by BBs about nerfs or from everyone else about any kind of buffs) I'd expect this one not to be an exception. So let me try to be ahead of it and actually explain why.   As it happens - just a few days ago I was researching how AP fuses work, and so I have a pretty good idea how this change came to be.   1st of all - yeah, as little as it might be it is a buff to an already heavily OverPerforming BB. Less armour to arm the fuse means more penetrations and less overpens, especially on lightly armoured ships (probably mainly cruisers for main batteries, DDs for secondaries). That can not be denied, but that's not the point.   So the change in question:   Since there is no mention of "AP fusing" in-game your best bet is to check Wiki - and surprisingly enough it's actually mentioned there (under "Gunnery & Armour penetration")   GC has 320mm main battery guns 120mm AP firing secondaries  - both values are not among those 4 given. Of course, we can try to see if there is any easily noticeable correlation between them by plugging those values into a graph:   There we get a linear progression by which we can calculate the armour thickness necessary to arm your AP shell fuses.   There comes a little sidenote I was informed about while talking to Game Mechanics Support   This standardization has been going on since 0.3.1 as mentioned wiki (keep in mind game went live over 2 years ago with patch 0.5.2 - so this is started either in Alpha or Closed Beta testing) and apparently it's still not quite done. Also during that conversation we ended up with the "best guess" being that those values are subject to normal rounding.   So, now if we plug in GCs gun calibers in the formula we end up with: 0.1644 * 320 + 0.5647 = 53.17 ≈ 53mm 0.1644 * 120 + 0.5647 = 20.29 ≈ 20mm Both of which happen to be the exact values they are being changed to.   So the is correct (altho that noticeable or not part could be debated)     So the better question(s) would be:   @MrConway Seeing how GC is one of the newest BBs in the game how comes it didn't already have correct fusing values at its introduction? And why is this standardization taking well over 2 years to fully implement?