Triple Overmatch
Triple overmatch is what players call “overmatch”. Most players don’t even know about double overmatch mechanics, so when you see or hear someone say the word “overmatch”, they are talking about the triple overmatch mechanic.
Triple overmatch is when its impossible for your tank’s shell to bounce off the enemy tank.
It happens when the caliber of your gun is 3 times larger than the armour plate you’re shooting at.
Example: In the image below, the Jg.E100 has a 40mm engine deck.
40 x 3 = 120
So any 122mm+ gun can overmatch this armour plate, since 122 > 120. The tank shooting the Jg.E100 is a 121, which has a 122mm gun.
Using Enhanced Armour can change this though, as it would make the engine deck 41.6mm, and 41.6 x 3 = 124.8. Since 124.8mm is larger than 122mm, the 122mm gun can no longer overmatch it.
-Overmatch does not work with HEAT or HE type rounds, only on AP.
-APCR can overmatch, however it is far less reliable than AP due to having less normalization (2 degrees instead of 5 degrees on AP). APCR will experience non-penetrations on overmatch areas much more often than AP does.
While triple overmatch means that your shell will never ricochet, it does not mean it will always penetrate.
There is a difference between a ricochet, and a non-penetration.
A ricochet is when the shell actually bounces off and continues travelling, a non-penetration is when the armour literally absorbs/stops the shell.
While its highly unlikely, (I have never seen it happen in all 8 years of playing WoT and WoT Blitz), its possible that an area where your shell can triple overmatch the enemy absorbs the shot (not a ricochet).
Due to this very high unlikeliness, generally all players consider the triple overmatch as meaning “the shell will always penetrate”, even though its not necessarily a 100% correct statement.
Double Overmatch
Double overmatch is when your gun caliber is at least 2 times larger than the armour plate thickness of the enemy. It increases your shell normalization, making it harder to bounce off.
The equation to calculate double overmatch is:
(shell normalization * 1.4 * gun caliber) / enemy armour plate thickness
For example:
If you are in a 60TP (152.4mm gun), using AP to shoot at a TVP T50/51’s frontal plate (75mm thick), instead of the usual 5 degree normalization of AP, you will get:
(5 * 1.4 * 152.4) / 75
= 14.22 degrees of normalization
Why is this important?
This is important against spaced armour plates, mainly the spaced armour plates that are directly next to the base armour plate.
This is probably one of the most important armour mechanics you can learn. While its hard to calculate in your head and in battle, you can estimate it based on the your gun size and the enemy’s spaced armour plate. You can see examples of the importance here.
The image below is a representation of how double overmatch affects the shell’s normalization on spaced armour.
Double overmatch is also the reason for tank tracks causing a tank to be weak when angling/sidescraping.
(This doesn’t happen in WoT PC, however it has been confirmed by WG support that it does happen in Blitz.
WG support’s answer for this is that its not a mistake, its just a game mechanic.)
Against base armour plates though, this mechanic is not at all important. That’s why so many players don’t know about this mechanic. The reasons for it being quite irrelevant against base armour are listed below:
1: Double overmatch only works up to the 70 degree auto-ricochet angle, at which point your shell would bounce anyway; unless it is 3 times larger than the armour plate it hits, at which point the shell would penetrate anyway due to triple overmatch.
2: It also only works if your gun caliber is actually more than 2 times larger than the thickness of the armour plate; so for the above example with the TVP, its limited to guns that are 150.1mm or larger (since the upper plate is 75mm).
3: Usually, if double overmatch mechanics apply, the armour plate is thin enough that your shell would penetrate anyway, and in the cases where its not penetrable, usually the plate is an auto-ricochet.
4: Gun calibers in the game only range from 12.7mm up to 183mm, meaning the maximum thickness plate which double overmatch mechanics still apply to are 91.4mm plates.Ā
Also consider, the most common gun calibers in the game are between 75mm and 130mm, meaning that most tanks can only use this mechanic against 37.4mm to 64.9mm plates.
Due to such constrained limits of this game mechanic, its not really noticed by players; and its not really useful against base armour. Its an extremely useful mechanic for dealing with spaced armour though.
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