Birst or Single ? little math tip

one bullet chance

main formula: P3=P1+P2-(P1*P2)

What is this showing exactly?

The chance of scoring a hit is the sum of the individual short probabilities so I just fire whatever combination of shots maxes this out. Burst firing gets through a lot of ammo but I haven't ever actually run out.

You should use burst if you can in this game..

The chance of scoring a hit is the sum of the individual short probabilities

Actually, no, it's not the sum of the individual hit chances. If it were, any time you had 34% or more with a 3-round burst or 10% or more with a heavy weapon, you would be guaranteed to hit (34% * 3 = 102%; 10% * 10 = 100%).

The actual chance of at least one hit is 1 - ((1 - per-shot hit chance) ^ (number of shots)). So 3 shots at 34% is a 1 - (0.66^3) = 71% chance of at least one hit and 10 shots at 10% is 1 - (0.9^10) = 65%. If you run this calculation for the values in the original post's chart, you'll see that the chart shows the probability of landing at least one hit.

The sum of individual hit chances gives you the expected average number of hits, after taking both the chance of a total miss and the chance of multiple hits into account. (10 shots at 10% is more likely to completely miss than 3 shots at 34%, but it's also more likely to score multiple hits, so the average number of hits ends up being approximately the same.)

Thanks for the explanation - yeah, I was oversimplifying because usually ICBA to work it out properly.

All other thing being near enough equal, bursts do seem to make more sense. If you have your 71% probability of a 1 hit from 3 rounds verses a hypothetical 71% chance of a hit with an aimed single shot, the two usually being about the same in TUs in my game so far, then the burst makes more sense. The single shot offers a maximum of one hit whereas the 3-round burst offers the possibility, even if small, of more.

Thanks for the explanation - yeah, I was oversimplifying because usually ICBA to work it out properly.

All other thing being near enough equal, bursts do seem to make more sense. If you have your 71% probability of a 1 hit from 3 rounds verses a hypothetical 71% chance of a hit with an aimed single shot, the two usually being about the same in TUs in my game so far, then the burst makes more sense. The single shot offers a maximum of one hit whereas the 3-round burst offers the possibility, even if small, of more.

Well, yeah, but if you fire three times as many shots, you run out of ammunition three times as fast. Even if you have plenty of spare ammo, taking the time to reload is painful when you have a Reaper bearing down on you.

My rule of thumb is: if you have a high hit probability and you must kill an alien, then use burst fire. The classic case is when you rush an alien with a rifle armed Xenonaut. If you have no-one else who can take out the alien if your Xenonaut misses, then definitely use burst fire. Don't die wondering whether one more shot would have given you a hit, or a second hit would have given you a kill. But blazing away your ammunition from range with a 20% probability of hitting is usually pointless, and if you run out of ammo at a bad moment, can be positively dangerous.

There is another thing to consider. The x3 burst has the same probability - per shot, mind you - as the snap shot. And with no movement, you have time for one x3 burst plus an additional snap shot. That makes it up to four rounds fired. The regular shot has a somewhat higher probability, and the aimed shot higher probability still. With no movement, you then have time for either four snap shots (including the burst), or one aimed and one regular shot.

I'll have to get home to find out exactly how much improved the regular and aimed shots are, before I could calculate which has the better chance of landing at least one hit: four low-% shots or two not-so-low-% shots.

Normally, though, I reserve burst fire to pretty much point blank range, and then usually against androns or enemies that need to die now.