Do Soviet BBs have good vertical dispersion?

[TheNPUKy]

Probably, Yes. 
Soviet BBs likely have a tight vertical dispersion which enables a player to hit the broadside of an enemy ship effectively.

I have tested in a training mode. Here are the digitized plots of the salvos (100 hits) on the surface at 10 and 15 km of distances. Sinop (Soviet Tier 7 BB) significantly outperforms Ashitaka and Bismarck (=Gneisenau) in vertical dispersion while its horizontal dispersion is the worst.
Note that it is an apparent vertical dispersion projected onto the horizontal surface. The true vertical dispersion is the dispersion on a vertical plane which is hard to test.


Fig. 1. The results of firing at 10 km with the three ships. The shells were fired from the bottom to top. Sinop outperforms others with the tight concentration of salvos at the centre of the y-axis. Ashitaka performs best in horizontal dispersion thanks to both good sigma and small max dispersion (See the table).  However in terms of vertical dispersion, Ashitaka falls to the bottom probably because IJN BBs are supposed to have bad vertical dispersion (source). Bismarck has a long tail of dispersion due to its low-flying shells.

Fig. 2. The results of firing at 15 km with the three ships. The Sinop still leads the rivals in vertical dispersion while its horizontal dispersion is exceptionally bad probably due to the combination of broad max dispersion and low sigma. 

	Sigma	Max radius in horizontal dispersion (x2.0 when it is not locked)	Impact angle (via wowsft.com)
Sinop (10km)	1.6	150 m	8.3 degree
Ashitaka (10km)	1.8	156 m	7.7 degree
Bismarck (10km)	1.8	164 m	6.7 degree
Sinop (15km)	1.6	210.5 m	16.0 degree
Ashitaka (15km)	1.8	192.0 m	14.9 degree
Bismarck (15km)	1.8	213.0 m	12.2 degree

Methods

1. Hopping into the training mode
2. Firing onto the cap area cone at the desired distance
3. Screengrabbing the salvo from above with replays
4. Digitizing them in GIS software
5. Some math and coding to normalize them

Please never ask me to do 1000 hits :P