[TorpX]

Originally Posted by Crannogman

That said, the Dick O'Kane method would suggest that the tics are reasonably reliable when the range is short and the AOB is minimal

I based my statement about the hash marks on CapnScurvy's exhaustive work on manual targeting accuracy with the stadimeter and telemeter marks. It is worth delving into, if you plan on using the telemeter marks.

Also, your fish goes a ways before its gyro turns it, plus there's the distance between your scope and the tubes. So, the closer to dead ahead you are shooting, the better.

Yes, I mentioned parallax error. And I assume that Spraug knows the fish and tubes displace the torpedo track forward/backwards from the scope.

It is a myth that one must shoot targets "dead ahead" to obtain success. This is neither true in real-life, nor in this game. Really, the development of the USN's TDC, to say nothing of torpedoes that could turn, would have been wasted effort, if that were the case.
There are alternate methods, apart from the "Dick O'Kane method" that do not rely on the game TDC's calculations, like THIS, for instance.