In the heat of battle you have to make all kinds of on the spot decisions. Sometimes these are judgment calls with no analytically right or wrong answer – you just go with what feels right. However, sometimes even very good players do this in situations where a bit of thought would lead them to a definitively right choice.
For example, during the 2012 ETC, my opponent and I were discussing a cover save for a squad of my chaos marines. I contended that they were in 4+ cover, he said no. After some debate he offered me to ‘4+ it’ to determine if they were in cover, to which I offered a flat 5+ cover save which he accepted. In a later game the same situation arose with a squad of Obliterators, this time I agreed to ‘4+ it’. So here’s a simple question for you:
Was I right to take a different approach to two seemingly identical situations?
In the case of marines, they needed cover to have any save at all, rolling a 4+ to see if they are in cover of 4+ needs two 4+s which is only 25% likely. Arguing for a 5+ got me a 33% survival chance. So heres a rule of thumb, if your opponent offers a 4+ on 4+, offer a flat 5+. If an opponent asks for a 5+ get him to 4+ it instead.
Then why the change for the Obliterators? Well, like all good rules of thumb, you need to know your exceptions. The key difference is that if the Obliterators aren’t in cover, they still have their 5+ invulnerable – arguing 5+ cover would achieve nothing. I should roll for the 4+ to try for 4+ cover and if I’m not in cover then I can still use the invulnerable.
There was a similar situation against Imperial Guard. The IG order “Fire on my target” forces you to reroll successful cover saves. A quick bit of math and I chose the 5+ invulnerable vs 4+ cover, for the same statistical reasoning as before – a 33% chance of survival vs a 25% chance.
Whenever you find yourself in these kinds of situation, take a moment to think about it – because eking out a few extra percentage points can win you a tight game, and aren’t those the best victories?