Board Thread:Questions and Answers/@comment-11700680-20171016171734/@comment-26366865-20171016201719

From your list, in no particular order: proto 35.6cm, proto 41cm, 38cm Twin Kai, quint torps, Akigun, 20.3cm (No.2), 20.3cm (No.3), AP shells, Iwamoto and Iwai fighters, T21 (skilled), T13 Radar Kai, T22 Radar Kai 4, T32 Radar, T3 Sonar and DC. I might have missed something, but these all should keep you busy for a while. The basic 12.7cm and the inferior ASW equipment are definitely wasted improvements.

There are some guidelines you can follow when choosing what to upgrade, but the most important one concerns what not to improve: basically, if there is a piece of equipment that is strictly better than another, and said equipment can be obtained without using screws, then you have no reason to ever upgrade the inferior one.

For example, the basic 12.7cm is inferior to both the Poigun, which you can easily grind for, and the Akigun, which is consistently available for farming during events. Therefore, there’s simply no reason to ever upgrade the basic 12.7cm. Same logic applies to Medium guns, torpedoes, ASW and Radars, though it gets messy when considering Heavy guns.

When choosing the order in which to upgrade stuff, the most important factor is how often you’re going to use it. This is why pretty much everyone recommends starting the upgrades with main guns: they’re going to get used whenever you sortie a ship of the class that can use it. Having a MAX piece of equipment just sitting in your storage provides no benefits to your fleet.

Another important point: having a bunch of +1 guns is better than having a single gun at +9; the latter will only provide +3 FP and ACC, while 9 +1 guns will provide +9 of each spread across the fleet, which is generally preferable. Thus, upgrading in steps (all to +1, then +4, then +9) is usually a better investment (planes are an exception IMO). Just be careful not to upgrade more than you can use – for example, having more than 5 pairs of upgraded Small guns is really unnecessary.

These are just some general pointers to get you started, since a detailed breakdown would be far too exhausting, but feel free to ask if you need a particular detail clarified.