Diablo – When does Sharpshooter become useless

Here is how you can think about sharpshooter:

1. It guarantees a critical hit within 33 seconds (less if you have higher base crit).
2. It lasts for a short time after your first critical hit (so if you have lots of arrows in the air you can crit for a if they strike near simultaneously). This is why nether tentacles are so great.
3. The breakpoint between whether or not to use it depends entirely on your crit chance, crit hit damage, and attack speed.

Here's some sample math to break it down (intentionally kept simple so take this with a large grain of salt):

Lets assume you have 20% chance to crit base with 200% crit damage and 2 attacks per second. There is only a single enemy for you to hit.

With 20% chance to crit and 2 attacks per second and no SS, you'll have, on average, 2.5 seconds between critical shots. This means sharpshooter translates roughly into 6-9% critical chance. This roughly translates into 12-18% more damage. This is pretty on par with cull the weak.

If your crit chance goes up, say to 50% (very hard to achieve and you'll either sacrifice a lot of dex/life or gold to buy the godly stuff), then on average you'll be critting every second, so SS only gives an additional 3% crit, meaning its only a 6% damage boost.

So in a sustained fight, you should not use SS in scenario 2 but use SS in scenario 1. However, also keep in mind SS gives you a huge damage spike at the beginning of every fight (guaranteed crit for 200% damage for 1 hit). I'd say for normal monster fighting (almost all the time on inferno) SS is great. For sustained fights such as with bosses, then SS is not as useful and then you'd go with cull the weak.

Finally, keep in mind cull the weak requires a slow of some kind, possibly using up an additional slot or rune where SS works on everything.

I disagree with the premise that SS will become useless as a glass cannon DH, starting out the fight strong is always important. If you can take things out within seconds, there's less chance of something getting close enough to kill you.