When it comes to popularity all tanks are not created equally. One can go for several Tier VI matches without seeing an ARL 44, ARL V39, Churchill VII, VK3001P, or SU-100, just to take some semi-random examples. For certain other tanks though it is a surprise if you do not see them every match where there are more than just two or three tanks of that tier – and at Tier VI the KV-1S reigns supreme, with only the VK3601H as a possible equal. This tank is reliably present on nearly any match involving Tier VI tanks. My understanding is that it is even more popular in Company battles.
Ultimately it is easy to see why the KV-1S is so popular – it is all down to the 122mm D-2-5T gun. A beast of a weapon this whacks an almighty whallop that can really upset the Tier VIII tanks it will encounter as well as ruin anything below tier. Having now elited it, I can certainly see why this configuration is so popular. Indeed I have pretty much used that gun ever since I unlocked it, but think the attraction of the KV-1S goes beyond just having a big gun.
A little history – the KV-1 was the first heavy tank to really prove itself in the field of battle. It was, for its time, massively heavily armoured, and fairly slow. This was, however, a time of rapid development in all military endeavours, and tanks were no exception, and after 1941 the KV-1 was starting to show its age. Its armour was no longer reliable, and its slow speed a handicap. The Russian engineers then modified the tank and created the KV-1S. This variant was designed to be more mobile, and sacrificing armour to get the additional speed, whilst also upgrading other features to reflect experience. A little later the designers further modified the KV idea and came up with the KV-13, which was a true medium, and also the Soviets developed the IS line of heavy tanks, which apart from everything else were rather more mobile than the older KV series. The KV-1S was upgraded again as the KV-85 and used to help bridge the gap between the older KV tanks and the new IS tanks. What we often get in World of Tanks is the KV-85 with an experimental gun fitted.
In other words, the KV-1S is very much a transitional tank. In game this is what it feels like. It is much speedier than its Tier VI counterpart, the T-150, at the cost of the armour. It does not, however, have the full mobility of a true medium, nor does it have the advanced armour features that made the IS-line so effective. It just hints to the future without ever getting there.
In terms of gameplay this means one should not pay too much attention to this being a “heavy” tank – it is perhaps best to think of it as a heavy medium. You do have that extra speed, and since the KV-1S does not have the armour to reliably bounce incoming fire that extra speed is vital get the best out of this tank.
As mentioned earlier the 122mm gun is by far the most popular choice of weapon, but it comes with one very serious drawback – a very long reload time. Even in one-on-one fights this can be a considerable difficulty. Say you and an opponent come up against each other – you shoot and hit, and your opponent loses half his health. He hits you and you lose maybe 1/6th of your hp. Then he starts to circle, hits you again, hits you again, and because you are likely tracked and your turret turns relatively slowly you may never get that second shot off. Also, if that first shot happens to miss or bounce (and despite the good penetration you will bounce same-tier tanks from time to time) then things very quickly start to look very grim. The gun also has a poor aim time and poor accuracy, and while these are also problems they are relatively minor inconveniences next to that long reload. Where this tank shines though is when two or three of them operate together. Three penetrating shots from a KV-1S with the 122mm will kill everything at Tier (apart from the TOG II* with its massive hp buffer), and also quite a few Tier VII vehicles. Another tactic would be for the tanks to fire consecutively one after other, separated by a few seconds. This way they could keep up a constant rate of fire of that massive gun, and with good focus of fire again tear the enemy apart. I have benefited from such tactics my tanks on my team, and been on the receiving end of them.
However, some players prefer to fit the 85mm D-5T, and the more I have thought this afternoon about this the more I am sorry I did not give it more of a try. The 85mm has less penetration (average 120mm compared to 175mm), but still more than enough for at Tier opponents, and plenty good enough if you manage to hit weakspost and / or flank higher tier opponents. Its damage is also less than half (average of 160 compared to 390). However its rate of fire is more than four times faster – all of which means its potential damage output is something like double that of the 122mm D-2-5T. Certainly one has potential to do some real damage there, and if one players the tank more like a flanking medium in the higher-tier battles I can see the potential for good things. However, for me this is going to remain theory as I will probably shortly be selling off my KV-1S to get the IS.
I end my run with the KV-1S after 76 matches, 43 of which were victories, and 75 enemy kills. Along the way I earned 1 Sniper and 4 Steel Wall medals, but the most I ever killed in a match was 4. That big gun allows you to dish out damage, but often the slow reload also means one will miss out on kills. I have enjoyed playing it, but it is time to move on.