[Bullethead]

This is a tough scenario for the IJN. The problem is that if you get in close enough to launch torps, or if you hang around to lauch a lot of torps, you're going to lose some or many DDs. The historical results of only 3 hits and no IJN losses was, IIRC, due to the Russians waking up and shooting furiously, which made most of the IJN DDs stay too far away to hit anything, but most of them weren't hit, either. I could be wrong, but I think the only IJN torp hits came early on, while they still had at least some surprise.

The key to this battle is how long it takes the Russians to spot the IJN. The Russians only sound GQ and start counting down their surprise timers AFTER 1 ship spots an IJN DD. Thus, the closer the IJN can get before being spotted, the better for them.

An important part of remaining invisible is the speed of the IJN DDs. The faster they go, they easier they are to see. Coal-burning DDs and TBs of their era had very short funnels so at high power they had a lot of incomplete combustion in the boilers. This hot, unburned gas would burst into flames as it left the funnel, lighting up the ship. This is why the IJN DDs start out at slow speed, and why the AI keeps them slow until they're spotted.

Being end-on to the enemy also makes you harder to see. So when I play the IJN, what I normally do is turn the flotillas in succession parallel to the Russian line, then turn them together to make the approach at 10 knots or even 8 in line abreast. Once I get about 1200m from the Russians (assuming I haven't yet been spotted), I turn them all together back parallel to the Russians, launch, then turn together and withdraw while accelerating to top speed. This allows all the DDs to start running away at once instead of the tail-end charlies being stuck in murder range while the leaders run. And of course each DD can launch at a different Russian.

The important targets for the IJN are the cruisers on the outer, most vulnerable row: Askold, Boyarin, and Novik. Sinking Russian BBs and the slower cruisers isn't very important in this battle because your main units can usually deal with them. If you go for the Russian BBs, you're going to lose most of your DDs because you have to get in deep and won't be able to get out before you start taking lots of fire.

However, even sinking the Russian cruisers isn't THAT critical at this stage, and isn't worth losing a lot of DDs over. So if the Russians spot you early on the way in, just break off the attack and go home without launching.